[Feature] Concurrent DB Connections and Transactions

[stevensJourney]

This PR updates SDK packages to use concurrent SQLite connections and transactions from powersync-ja/react-native-quick-sqlite#2

Some API changes are made in this PR:

• Removal of synchronous DB operations in transactions: execute, commit, rollback are now async functions. executeAsync, commitAsync and rollbackAsync have been removed.
• Transaction contexts now have get, getAll and getOptional helpers.
• Added a default lock timeout of 2 minutes to aide with potential recursive lock/transaction requests.

Testing:
This has been tested with the Supabase Todo list app. Automated tests are currently a work in progress on the unit_tests branch.

TODO:

• Bump package versions.