[wip]: feat load env for any variables

[avallete]

What kind of change does this PR introduce?

Attempt to re-use similar logic as in LoadRemoteConfigOverrides to unify the "env variables" loading logic across all the config.

What is the current behavior?

Please link any relevant issues here.

What is the new behavior?

Feel free to include screenshots if it includes visual changes.

Additional context

Add any other context or screenshots.

[coveralls]

Pull Request Test Coverage Report for Build 10959929592

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 3 of 5 (60.0%) changed or added relevant lines in 1 file are covered.
• 14 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.1%) to 60.041%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/utils/config.go	3	5	60.0%

Files with Coverage Reduction	New Missed Lines	%
internal/gen/keys/keys.go	5	12.9%
internal/utils/config.go	9	84.16%

Totals
Change from base Build 10919817737:	-0.1%
Covered Lines:	6449
Relevant Lines:	10741

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💛 - Coveralls