refactor(server): unify URL configs when scheme is missing

[bitflicker64]

Purpose of the PR

• close [Improvement] unify endpoint URL format #2942
• Some server URL configs currently require an explicit scheme (http:// / https://). If a user sets something like 127.0.0.1:8080, it can fail to parse or behave inconsistently compared to other modules that already default the scheme.

This PR fixes that by normalizing only the relevant server URL options: if the scheme is missing, we auto-prefix a sensible default, while leaving explicitly provided schemes untouched.

Also covered the review corner case: server.k8s_url should default to https:// (so we don’t accidentally downgrade it to http://).

Main Changes

HugeConfig.get(...) now applies URL normalization for a small allowlist of keys:

• restserver.url → default http://
• gremlinserver.url → default http://
• server.urls_to_pd → default http://
• server.k8s_url → default https://

Normalization only triggers when:

• the config key is in the allowlist, and
• the value is a String, and
• the value has no scheme

If the value already starts with http:// or https://, it’s left as-is.
Non-string config values are untouched.

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• Already covered by existing tests, such as (please modify tests here).
• Need tests and can be verified as follows:
  Tests are included and you can verify the behavior like this:

• Added unit tests in HugeConfigTest covering:

  • missing scheme → default prefix is added
  • existing scheme → preserved as-is
  • server.k8s_url missing scheme → becomes https://... (no accidental downgrade)

Does this PR potentially affect the following parts?

• Dependencies (add/update license info & regenerate_known_dependencies.sh)
• Modify configurations
• The public API
• Other affects (typed here)
• Nope

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need