Notifications: inline error message on notifications saving error (#10288)

* basic sync setup

* formatting

* get loudest value for synced rules

* more types

* test synced rules in notifications settings

* type fixes

* noimplicitany fixes

* remove debug

* tidying

* extract updatePushRuleActions fn to utils

* extract update synced rules

* just synchronise in one place?

* monitor account data changes AND trigger changes sync in notifications form

* lint

* setup LoggedInView test with enough mocks

* test rule syncing in LoggedInView

* strict fixes

* more comments

* one more comment

* add error variant for caption component

* tests for new error message

* tweak styles

* noImplicitAny

* revert out of date prettier changes to unrelated files

* limit inline message to radios only, tests

* strict fix

res/css/components/views/typography/_Caption.pcss

@@ -17,4 +17,8 @@ limitations under the License.
 .mx_Caption {
     font-size: $font-12px;
     color: $secondary-content;
+
+    &.mx_Caption_error {
+        color: $alert;
+    }
 }