add compareSubstring, compareSubstringIgnoreCase and adopt for search tree so that it will be fit for case-in-sensitive compare, https://github.com/microsoft/vscode/issues/93368

allow compareIgnoreCase to operate on substrings, touches on https://github.com/microsoft/vscode/issues/93368

We set alwaysStrict so this directive is not needed

Standardizing syntax and discouraging use of `this` inside tests

This reverts commit 27256832 which turns out did not break the import of vs/nls

This reverts commit 7de696a2.

Seems to have broken loading vs/nls in at least one case in insiders

Don't use this import form in places where it is not needed. This prevents us from correctly detecting duplicate imports

Fix #27802 - show a warning for a regex that contains a backreference. Ripgrep interprets this as an octal escape sequence, instead of a backreference.