Change default TS object bindings

[joegm]

Implements https://github.com/helix-editor/helix/issues/165#issuecomment-1216566867

Changes 'match inside/around' bindings for:

• type definition from c to t
• comments from o to c
• tests from t to T

Also changes those for the ] / [ bindings.

[David-Else]

This makes SO much sense! I hope it can get in before the next release so new users don't have to learn the current key bindings.

[dead10ck]

This seems like a good change to me 👍