7c6ff517d5
This patch introduces the `sqlite` and `indexeddb` feature flag, enabling the use of SQLite or IndexedDB for the stores. This patch also introduces the ability to use non-persistent, in-memory stores. The new `ClientBuilder::in_memory_store`, `ClientBuilder::sqlite_store` and `ClientBuilder::indexeddb_store` methods are introduced to configure the stores. This patch adds new `SqliteStoreBuilder` and `IndexedDbStoreBuilder` structure.