fix: Searchbar focus()

[wodCZ]

Closes #2393; Closes #2394

Summary

For some reason, returning the reference to underlying method raises dispatchCommand was called with a ref that isn't a native component error and doesn't actually focus the input.

Returning new proxy method works as expected (and allows us to remove @ts-ignore too).

Test plan

Not sure about testing, just wanted to get things moving.

[karimcambridge]

Can we fix this in the next version? It's been broken for a long time

[raajnadar]

@wodCZ can you fix the merge conflicts!

[wodCZ]

@raajnadar rebased, didn't have time to actually test the rebased version though.
The change remains the same - instead of forwarding the original handler, wrap it in a new callback.

[wodCZ]

Ok, I've just updated the app where we use this, and can confirm that the issues are still present in react-native-paper 4.7.2, and can confirm that this change fixes the behavior.

@raajnadar is there anything I can do to get things moving?