feat(htpasswd): add autoreload for htpasswd

[vooon]

What type of PR is this?

feature

Which issue does this PR fix:

Fix #2925

What does this PR do / Why do we need it:

If an issue # is not available please add repro steps and logs showing the issue:

Testing done on this change:

Automation added to e2e:

Will this break upgrades or downgrades?

Does this PR introduce any user-facing change?:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[vooon]

Unsure, htpasswd change do not require full reload with server restarts. But putting the logic into existing watcher much easier.
And in my case the event is not very often.

[vooon]

Looks like it works, but not as fast as file updates.

[codecov]

Codecov Report

Attention: Patch coverage is 84.25926% with 17 lines in your changes missing coverage. Please review.

Project coverage is 91.02%. Comparing base (d0ad935) to head (259df17).

Files with missing lines	Patch %	Lines
pkg/cli/server/config_reloader.go	22.22%	12 Missing and 2 partials ⚠️
pkg/api/htpasswd.go	94.33%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2933      +/-   ##
==========================================
- Coverage   91.06%   91.02%   -0.04%     
==========================================
  Files         174      175       +1     
  Lines       32655    32725      +70     
==========================================
+ Hits        29736    29789      +53     
- Misses       2207     2221      +14     
- Partials      712      715       +3     

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[rchincha]

Ideally, we need the watching logic to move outside the server/controller logic, so it is just another config file we watch (along with zot config)

That could be second step. Let other folks take a look also.