Support a module API surface for custom functionality (#8246)

* Early implementation of module API surface + functions for ILAG module

* Wire up dialog functions and ILAG-needed surface

* Ensure component renders for modules get overridden

* Respond to changes from module API interface

* Use a real module-api dependency

* Update for new Dialogs interface

* Add support for getConfigValue from module API

* Update the remainder of the module API interface

* Docs & cleanup

* Add some unit tests around module stuff

Needs end-to-end tests still.

* Appease early linters

* Break import cycles by not directly depending on Lifecycle

* Appease the linter

* Fix bad merge

src/modules/ModuleRunner.ts

@@ -0,0 +1,85 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { TranslationStringsObject } from "@matrix-org/react-sdk-module-api/lib/types/translations";
+import { AnyLifecycle } from "@matrix-org/react-sdk-module-api/lib/lifecycles/types";
+
+import { AppModule } from "./AppModule";
+import { ModuleFactory } from "./ModuleFactory";
+import "./ModuleComponents";
+
+/**
+ * Handles and coordinates the operation of modules.
+ */
+export class ModuleRunner {
+    public static readonly instance = new ModuleRunner();
+
+    private modules: AppModule[] = [];
+
+    private constructor() {
+        // we only want one instance
+    }
+
+    /**
+     * Resets the runner, clearing all known modules.
+     *
+     * Intended for test usage only.
+     */
+    public reset() {
+        this.modules = [];
+    }
+
+    /**
+     * All custom translations from all registered modules.
+     */
+    public get allTranslations(): TranslationStringsObject {
+        const merged: TranslationStringsObject = {};
+
+        for (const module of this.modules) {
+            const i18n = module.api.translations;
+            if (!i18n) continue;
+
+            for (const [lang, strings] of Object.entries(i18n)) {
+                if (!merged[lang]) merged[lang] = {};
+                for (const [str, val] of Object.entries(strings)) {
+                    merged[lang][str] = val;
+                }
+            }
+        }
+
+        return merged;
+    }
+
+    /**
+     * Registers a factory which creates a module for later loading. The factory
+     * will be called immediately.
+     * @param factory The module factory.
+     */
+    public registerModule(factory: ModuleFactory) {
+        this.modules.push(new AppModule(factory));
+    }
+
+    /**
+     * Invokes a lifecycle event, notifying registered modules.
+     * @param lifecycleEvent The lifecycle event.
+     * @param args The arguments for the lifecycle event.
+     */
+    public invoke(lifecycleEvent: AnyLifecycle, ...args: any[]): void {
+        for (const module of this.modules) {
+            module.module.emit(lifecycleEvent, ...args);
+        }
+    }
+}