Pocketbase v0.23.0-RC Prerelease

Gani has done a great job of keeping folks in the loop about upcoming changes and the thought process behind them, see this thread for more context: https://github.com/pocketbase/pocketbase/discussions/4355#di...

Lots of internal changes. I'm not entirely sure how removing Echo will help the project, though..

I'm excited to see what's the Batch api going to look like. I have a few projects that definitely need it to make operations atomic.

Also, readonly/hidden fields are a great addition!