Add missing sqlite3_context_db_handle() JS binding. Reimplement sqlite3_set_authorizer() and sqlite3_set_auxdata() JS bindings to take advantage of [7f9ace1b11a67]. Teach FuncPtrAdapter to emit a console.warn() message if it is invoked after the library is bootstrapped, the goal being to inform users that it's an internal API and should not be invoked from client-side code.

FossilOrigin-Name: 8e3d4f6294037396e388ec21abb18bf0201a6bec6ff004730cc5d11b705a6d2b