Rename all @BindingContainer types with a BindingContainer suffix

Metro's @BindingContainer replaced Dagger's @Module, but the declarations
kept the old Module suffix. Rename them (and their dedicated files) so the
type name matches the annotation, matching UserStatusBindingContainer which
already followed this convention.

No behaviour change: Metro discovers containers via @ContributesTo, so there
were only two call sites to update, both in tests.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

annotations/src/main/kotlin/io/element/android/annotations/ContributesNode.kt

@@ -16,7 +16,7 @@ import kotlin.reflect.KClass
  *
  * @BindingContainer
  * @ContributesTo(Scope::class)
- * abstract class YourNodeModule {
+ * abstract class YourNodeBindingContainer {
 
  *  @Binds
  *  @IntoMap