Add locale to toLocaleLowerCase calls

[koesie10]

This adds the locale to all toLocaleLowerCase calls. The three calls to toLocaleLowerCase were all very similar, so I've created a function to abstract this behavior. Now, we only have 1 call to toLocaleLowerCase and have simplified the logic for checking environment variables.

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.