separate interceptors; added language interceptor for api responses

core/datastore/src/main/kotlin/com/meloda/app/fast/datastore/UserSettings.kt

@@ -13,6 +13,7 @@ interface UserSettings {
     val online: StateFlow<Boolean>
     val debugSettingsEnabled: StateFlow<Boolean>
     val useContactNames: StateFlow<Boolean>
+    val language: StateFlow<String>
 
     fun updateUsingDarkTheme()
     fun useDarkThemeChanged(use: Boolean)
@@ -24,6 +25,7 @@ interface UserSettings {
     fun setOnline(use: Boolean)
     fun enableDebugSettings(enable: Boolean)
     fun onUseContactNamesChanged(use: Boolean)
+    fun onLanguageChanged(newLanguage: String)
 }
 
 class UserSettingsImpl(
@@ -69,6 +71,8 @@ class UserSettingsImpl(
         )
     )
 
+    override val language = MutableStateFlow("")
+
     override fun updateUsingDarkTheme() {
         useDarkThemeChanged(
             isUsingDarkMode(
@@ -117,4 +121,8 @@ class UserSettingsImpl(
     override fun onUseContactNamesChanged(use: Boolean) {
         useContactNames.update { use }
     }
+
+    override fun onLanguageChanged(newLanguage: String) {
+        language.update { newLanguage }
+    }
 }