Add global context.cacheDir provider. (#1606)

## Type of change

- [ ] Feature
- [ ] Bugfix
- [x] Technical
- [ ] Other :

## Content

Dagger now provides the app's `cacheDir` when requesting a `@CacheDirectory File`  type.

## Motivation and context

To support some upcoming code that needs the `cacheDir` to be changed during tests.

app/src/main/kotlin/io/element/android/x/di/AppModule.kt

@@ -31,6 +31,7 @@ import io.element.android.libraries.core.meta.BuildType
 import io.element.android.libraries.designsystem.utils.snackbar.SnackbarDispatcher
 import io.element.android.libraries.di.AppScope
 import io.element.android.libraries.di.ApplicationContext
+import io.element.android.libraries.di.CacheDirectory
 import io.element.android.libraries.di.DefaultPreferences
 import io.element.android.libraries.di.SingleIn
 import io.element.android.x.BuildConfig
@@ -51,6 +52,12 @@ object AppModule {
         return File(context.filesDir, "sessions")
     }
 
+    @Provides
+    @CacheDirectory
+    fun providesCacheDirectory(@ApplicationContext context: Context): File {
+        return context.cacheDir
+    }
+
     @Provides
     fun providesResources(@ApplicationContext context: Context): Resources {
         return context.resources