Refactor persistent data storage code and add button to wipe data on crash (#827)

* Organize persistence.ts

* Switch to simpler promise handling

* Switch document list storage from localStorage to IndexedDB

* Track document auto-save status to avoid re-auto-saving unnecessarily

* Add button to clear storage on crash

* Bump document version and test file

* Switch to IDB-Keyval instead of raw IDB transactions

frontend/wasm/src/editor_api.rs

@@ -207,6 +207,7 @@ impl JsEditorHandle {
 		let message = PortfolioMessage::OpenDocumentFileWithId {
 			document_id,
 			document_name,
+			document_is_auto_saved: true,
 			document_is_saved,
 			document_serialized_content,
 		};