terminal: Fix non regex search to actually be non regex (#7330)

Alacritty seems to support only regex search out of the box.
This PR just escapes all special regex chars to make non regex search
work as expected.
Disclaimer: New to Rust.

Release Notes:

-Fixed text search not working correctly in terminal ([#4880](https://github.com/zed-industries/zed/issues/4880))
b4b59f8706N8th8n8el committed on 2/10/2024, 7:34:41 PM· committed by GitHubparent4f5fea5
1 file changedLine totals unavailable