feat: Allow force of basic auth for HTTP repositories

[jannfis]

Change introduces a new boolean setting for repositories: forceHttpBasicAuth. If set to true, Argo CD will make the Git client send an Authorization: Basic ... header to the repository server, thereby bypassing any authentication scheme negotiation done by Git (or libcurl, to be precise).

Closes #11914
Fixes #6289
Fixes #6362

Signed-off-by: jannfis jann@mistrust.net

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[codecov]

Codecov Report

Base: 47.30% // Head: 47.44% // Increases project coverage by +0.13% 🎉

Coverage data is based on head (8d235c7) compared to base (8917077).
Patch coverage: 45.65% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11983      +/-   ##
==========================================
+ Coverage   47.30%   47.44%   +0.13%     
==========================================
  Files         245      246       +1     
  Lines       41670    41860     +190     
==========================================
+ Hits        19712    19859     +147     
- Misses      19972    20002      +30     
- Partials     1986     1999      +13     

Impacted Files	Coverage Δ
cmd/argocd/commands/repo.go	0.00% <0.00%> (ø)
cmd/argocd/commands/repocreds.go	0.00% <0.00%> (ø)
cmd/util/repo.go	0.00% <0.00%> (ø)
server/repository/repository.go	51.49% <0.00%> (-0.13%)	⬇️
util/settings/settings.go	49.20% <ø> (+0.77%)	⬆️
util/git/client.go	49.43% <20.00%> (-0.23%)	⬇️
util/db/repository_secrets.go	68.35% <57.14%> (-0.44%)	⬇️
pkg/apis/application/v1alpha1/repository_types.go	71.42% <66.66%> (+0.39%)	⬆️
util/git/creds.go	50.31% <100.00%> (+1.45%)	⬆️
util/oidc/provider.go	34.42% <0.00%> (-20.12%)	⬇️
... and 10 more

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[jannfis]

@crenshaw-dev @leoluz @alexmt Could I get someone of you having a look at this PR please?

[crenshaw-dev]

lgtm, thanks @jannfis!

[crenshaw-dev]

Should we also update https://argo-cd.readthedocs.io/en/latest/operator-manual/declarative-setup/ and argocd-repositories.yaml with examples?

[jannfis]

Good thinking, I'll update this PR to include some docs. Thanks!

[crenshaw-dev]

Cherry-picked onto release-2.6 for 2.6.0-rc7.