* [web] Remove left/top/transform reset since all code paths now set ltwh
* Remove unused style var
* Handle path=null , address review comments
* Added comment for reset code

* Fix cachedLastStyle state leak across canvases. Reduce ctx.font reset calls.

* Remove font set test

This change is part of an LSC in Fuchsia, and is a functionality no-op.

Fixes fxbug.dev/50759
Co-authored-by: NGabriel Schine <thatguy@google.com>

This reverts commit b5aedb30 and relands #17712.

Fixes flutter/flutter#53288 and flutter/flutter#41654.

Together with #17791, this reland addresses some of Jim's concerns in the original PR #17712.

The major part of this PR is still the same as the original PR, and the performance / golden image impacts should be the same.