Move the custom tile server URL config to the Element wellknown content (#7416)

* Move the custom tile server URL config to the Element wellknown content

* Iteration: use whole `MapTilerConfig` in the remote config

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/MatrixClient.kt

@@ -255,11 +255,6 @@ interface MatrixClient : UrlContentFetcher {
      */
     suspend fun performDatabaseVacuum(): Result<Unit>
 
-    /**
-     * Returns the URL of the map style configured on the server, if any.
-     */
-    suspend fun getMapStyleUrl(): Result<String?>
-
     /**
      * Resets the cached client `well-known` config by the SDK.
      */