[lib] Replace BaseAppState<*> with default type param

Summary:
* is basically any in modern versions of Flow. This diff removes most of the uses of * in our codebase.

This came up in D8526 and D8644.

Depends on D8685

Test Plan: Flow

Reviewers: inka, michal, patryk

Reviewed By: patryk

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D8686