Use shared recent emoji reactions from account data (#5402)

* Use shared recent emoji reactions from account data

- Add `AddRecentEmoji` and `GetRecentEmojis` use cases to avoid injecting the whole `MatrixClient` for just one of these operations.
- Update the UI and logic of the emoji picker and message context menu to include the recent emojis.
- Add `CoroutineDispatchers.Default` with the defaults coroutines to use in the app for ease of use.

* Instead of replacing suggested emojis, concatenate recent ones removing duplicates

* Update screenshots

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Co-authored-by: ElementBot <android@element.io>

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/FakeMatrixClient.kt

@@ -97,6 +97,8 @@ class FakeMatrixClient(
     override val ignoredUsersFlow: StateFlow<ImmutableList<UserId>> = MutableStateFlow(persistentListOf()),
     private val getMaxUploadSizeResult: () -> Result<Long> = { lambdaError() },
     private val getJoinedRoomIdsResult: () -> Result<Set<RoomId>> = { Result.success(emptySet()) },
+    private val getRecentEmojisLambda: () -> Result<List<String>> = { Result.success(emptyList()) },
+    private val addRecentEmojiLambda: (String) -> Result<Unit> = { Result.success(Unit) },
 ) : MatrixClient {
     var setDisplayNameCalled: Boolean = false
         private set
@@ -349,4 +351,12 @@ class FakeMatrixClient(
     override suspend fun getMaxFileUploadSize(): Result<Long> {
         return getMaxUploadSizeResult()
     }
+
+    override suspend fun addRecentEmoji(emoji: String): Result<Unit> {
+        return addRecentEmojiLambda(emoji)
+    }
+
+    override suspend fun getRecentEmojis(): Result<List<String>> {
+        return getRecentEmojisLambda()
+    }
 }