* [cm6] Show Regex errors in find & replace
* cleanup, isInvalidRegExp function
* no state variable, less color var
* use @brand-dager
* using var(--ol-cm-search-form-focus-shadow)
* using state-danger-border
GitOrigin-RevId: 844c9dfee5a56d2a7494cd86c266acbe9eacd033