Pocketbase

- Added support for assigning a `Promise` as `AsyncAuthStore` initial value ([249](https://github.com/pocketbase/js-sdk/issues/249)).

- Fixed realtime subscriptions auto cancellation to use the proper `requestKey` param.

- Added `pb.backups.upload(data)` action (_available with PocketBase v0.18.0_).

- Added _experimental_ `autoRefreshThreshold` option to auto refresh (or reauthenticate) the AuthStore when authenticated as admin.
_This could be used as an alternative to fixed Admin API keys._
js
await pb.admins.authWithPassword("testexample.com", "1234567890", {
// This will trigger auto refresh or auto reauthentication in case
// the token has expired or is going to expire in the next 30 minutes.
autoRefreshThreshold: 30 * 60
})

- Loosen the type check when calling `pb.files.getUrl(user, filename)` to allow passing the `pb.authStore.model` without type assertion.

- Fixed mulitple File/Blob array values not transformed properly to their FormData equivalent when an object syntax is used.

- Fixed typo in the deprecation console.warn messages ([235](https://github.com/pocketbase/js-sdk/pull/235); thanks heloineto).