Implement MSC3575: Sliding Sync (#8328)

* Add labs flag for sliding sync; add sliding_sync_proxy_url to config.json

* Disable the labs toggle if sliding_sync_proxy_url is not set

* Do validation checks on the sliding sync proxy URL before enabling it in Labs

* Enable sliding sync and add SlidingSyncManager

* Get room subscriptions working

* Hijack renderSublists in sliding sync mode

* Add support for sorting alphabetically/recency and room name filters

* Filter out tombstoned rooms; start adding show more logic

list ranges update but the UI doesn't

* update the UI when the list is updated

* bugfix: make sure the list sorts numerically

* Get invites transitioning correctly

* Force enable sliding sync and labs for now

* Linting

* Disable spotlight search

* Initial cypress plugins for Sliding Sync Proxy

* Use --rm when running Synapse in Docker for Cypress tests

* Update src/MatrixClientPeg.ts

Co-authored-by: Travis Ralston <travisr@matrix.org>

* Update src/components/views/rooms/RoomSublist.tsx

Co-authored-by: Travis Ralston <travisr@matrix.org>

* Update src/settings/controllers/SlidingSyncController.ts

Co-authored-by: Travis Ralston <travisr@matrix.org>

* Update src/components/views/rooms/RoomSublist.tsx

Co-authored-by: Travis Ralston <travisr@matrix.org>

* WIP add room searching to spotlight search

* Only read sliding sync results when there is a result, else use the local cache

* Use feature_sliding_sync not slidingSync

* Some review comments

* More review comments

* Use RoomViewStore to set room subscriptions

* Comment why any

* Update src/components/views/rooms/RoomSublist.tsx

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

* Fix cypress docker abstraction

* Iterate sliding sync proxy support

* Stash mostly functional test

* Update sliding sync proxy image

* i18n

* Add support for spaces; use list ID -> index mappings

- Mappings are more reusable and easier to understand than
  racing for index positions.
- Register for all spaces immediately on startup.

* When the active space is updated, update the list registration

* Set spaces filter in the correct place

* Skeleton placeholder whilst loading the space

* Filter out spaces from the room list

* Use the new txn_id promises

* Ensure we actually resolve list registrations

* Fix matrix-org/sliding-sync#30: don't show tombstoned search results

* Remove unused imports

* Add SYNCV3_SECRET to proxy to ensure it starts up; correct aliases for SS test

* Add another basic sliding sync e2e test

* Unbreak netlify

* Add more logging for debugging duplicate rooms

* If sliding sync is enabled, always use the rooms result even if it's empty

* Drop-in copy of RoomListStore for sliding sync

* Remove conditionals from RoomListStore - we have SlidingRoomListStore now

* WIP SlidingRoomListStore

* Add most sliding sync logic to SlidingRoomListStore

Still lots of logic in RoomSublist. Broken things:
 - Join count is wrong completely.
 - No skeleton placeholder when switching spaces.

* Migrate joined count to SS RLS

* Reinstate the skeleton UI when the list is loading

* linting

* Add support for sticky rooms based on the currently active room

* Add a bunch of passing SS E2E tests; some WIP

* Unbreak build from git merge

* Suppress unread indicators in sliding sync mode

* Add regression test for https://github.com/matrix-org/sliding-sync/issues/28

* Add invite test flows; show the invite list

The refactor to SS RLS removed the invite list entirely.

* Remove show more click as it wasn't the bug

* Linting and i18n

* only enable SS by default on netlify

* Jest fixes; merge conflict fixes; remove debug logging; use right sort enum values

* Actually fix jest tests

* Add support for favourites and low priority

* Bump sliding sync version

* Update sliding sync labs to be user configurable

* delint

* To disable SS or change proxy URL the user has to log out

* Review comments

* Linting

* Apply suggestions from code review

Co-authored-by: Travis Ralston <travisr@matrix.org>

* Update src/stores/room-list/SlidingRoomListStore.ts

Co-authored-by: Travis Ralston <travisr@matrix.org>

* Review comments

* Add issue link for TODO markers

* Linting

* Apply suggestions from code review

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

* More review comments

* More review comments

* stricter types

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>
Co-authored-by: Travis Ralston <travisr@matrix.org>

src/MatrixClientPeg.ts

@@ -36,6 +36,7 @@ import * as StorageManager from './utils/StorageManager';
 import IdentityAuthClient from './IdentityAuthClient';
 import { crossSigningCallbacks, tryToUnlockSecretStorageWithDehydrationKey } from './SecurityManager';
 import SecurityCustomisations from "./customisations/Security";
+import { SlidingSyncManager } from './SlidingSyncManager';
 import CryptoStoreTooNewDialog from "./components/views/dialogs/CryptoStoreTooNewDialog";
 import { _t } from "./languageHandler";
 
@@ -237,6 +238,19 @@ class MatrixClientPegClass implements IMatrixClientPeg {
         opts.clientWellKnownPollPeriod = 2 * 60 * 60; // 2 hours
         opts.experimentalThreadSupport = SettingsStore.getValue("feature_thread");
 
+        if (SettingsStore.getValue("feature_sliding_sync")) {
+            const proxyUrl = SettingsStore.getValue("feature_sliding_sync_proxy_url");
+            if (proxyUrl) {
+                logger.log("Activating sliding sync using proxy at ", proxyUrl);
+            } else {
+                logger.log("Activating sliding sync");
+            }
+            opts.slidingSync = SlidingSyncManager.instance.configure(
+                this.matrixClient,
+                proxyUrl || this.matrixClient.baseUrl,
+            );
+        }
+
         // Connect the matrix client to the dispatcher and setting handlers
         MatrixActionCreators.start(this.matrixClient);
         MatrixClientBackedSettingsHandler.matrixClient = this.matrixClient;