fix: stricter validation for key names in default config

[knutties]

Problem

Currently we allow trailing spaces and special characters in key names which is typically not needed. This PR restricts the characters in the key name to the following regex: ^[a-zA-Z0-9-_.]{1,64}$

Solution

This PR uses the above regex to validate the key in the APIs - if found invalid - return a bad request response

Environment variable changes

NA

Pre-deployment activity

NA

Post-deployment activity

NA

API changes

Endpoint	Method	Request body	Response Body
API	PUT /config/key	same as existing with additional validations	same as existing

Possible Issues in the future

NA