Plain text editor implementation based on markdown input (#2840)

* Add plain text editor based on markdown input
- Fix autofocus of message composer.
- Remove `Message` data class, fetch the details in `MessagesPresenter` instead.
- Remove `enable rich text` option from advanced settings, set it as a build configuration instead.
* Fix MentionSpanProvider
* Bump RTE library to released `v2.37.3`

---------

Co-authored-by: ElementBot <benoitm+elementbot@element.io>

libraries/preferences/impl/src/main/kotlin/io/element/android/libraries/preferences/impl/store/DefaultAppPreferencesStore.kt

@@ -25,7 +25,6 @@ import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.datastore.preferences.preferencesDataStore
 import com.squareup.anvil.annotations.ContributesBinding
 import io.element.android.features.preferences.api.store.AppPreferencesStore
-import io.element.android.libraries.core.bool.orTrue
 import io.element.android.libraries.core.meta.BuildMeta
 import io.element.android.libraries.core.meta.BuildType
 import io.element.android.libraries.di.AppScope
@@ -36,7 +35,6 @@ import javax.inject.Inject
 
 private val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "elementx_preferences")
 
-private val richTextEditorKey = booleanPreferencesKey("richTextEditor")
 private val developerModeKey = booleanPreferencesKey("developerMode")
 private val customElementCallBaseUrlKey = stringPreferencesKey("elementCallBaseUrl")
 private val themeKey = stringPreferencesKey("theme")
@@ -48,19 +46,6 @@ class DefaultAppPreferencesStore @Inject constructor(
 ) : AppPreferencesStore {
     private val store = context.dataStore
 
-    override suspend fun setRichTextEditorEnabled(enabled: Boolean) {
-        store.edit { prefs ->
-            prefs[richTextEditorKey] = enabled
-        }
-    }
-
-    override fun isRichTextEditorEnabledFlow(): Flow<Boolean> {
-        return store.data.map { prefs ->
-            // enabled by default
-            prefs[richTextEditorKey].orTrue()
-        }
-    }
-
     override suspend fun setDeveloperModeEnabled(enabled: Boolean) {
         store.edit { prefs ->
             prefs[developerModeKey] = enabled