Feature Description

Currently Locals accepts only a string for key.

Fasthttp has merged my PR to change uservalues to accept Interface{} for key: valyala/fasthttp#1387 (comment)

Additional Context (optional)

See valyala/fasthttp#1385 (comment)

Code Snippet (optional)

No response

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my suggestion prior to opening this one.
• I understand that improperly formatted feature requests may be closed without explanation.