chore: improve exist api performance

[Kingwl]

The Error/Throw is very very slow (especially in a huge bundled javascript file)

This PR use a simple Result type to replace new control flow based on Error/Throw.

All tests has passed. Seems nothing broken.

This PR just replace the call tree of exists/existsSync . We can avoid more Error/Throw if everything looks good.

Before:

After:

Fixes #1217