Load only the currently needed JS locale file

What does this MR do?

It loads only the JS locale file of the currently selected language and removes our locale.bundle. It loads now 31.6kb for English instead of almost 1 MB.

Are there points in the code the reviewer needs to double check?

• Webpack Config

Why was this MR needed?

• To reduce the load to only the current language

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

closes #38470 (closed)