chore: run e2e tests with testcontainers

[blakepettersson]

This change allows for the use of testcontainers to run E2E tests. Why would we want this? Mainly for three reasons:

1. IDE friendlier
2. Debugger friendlier
3. Much easier to setup

It's a "one click" way (or a simple go test e2e way) to run E2E tests. To run using testcontainers, run go test e2e or make test-e2e-local - there is no need to do anything else.

This has a bunch of changes, but the majority of them is simply extracting the command flags from the affected controller commands to separate builders, which are then used for instantiating each controller programatically. The commands make use of these builders to set the flags as they previously did, so from a user perspective nothing changes.

Redis, K3S and the E2E server are run as testcontainers when running the E2E tests. The controllers are run in-process but spun off into separate goroutines.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• The title of the PR conforms to the Toolchain Guide
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).
• My new feature complies with the feature status guidelines.
• I have added a brief description of why this PR is necessary and/or what this PR solves.
• Optional. My organization is added to USERS.md.
• Optional. For bug fixes, I've indicated what older releases this fix should be cherry-picked into (this may or may not happen depending on risk/complexity).

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[codecov]

Codecov Report

Attention: Patch coverage is 23.83107% with 505 lines in your changes missing coverage. Please review.

Project coverage is 50.64%. Comparing base (a071f93) to head (6654416).
Report is 10 commits behind head on master.

Files	Patch %	Lines
cmd/argocd-server/commands/argocd_server.go	0.00%	180 Missing ⚠️
...ntroller/commands/argocd_application_controller.go	0.00%	139 Missing ⚠️
.../argocd-repo-server/commands/argocd_repo_server.go	0.00%	130 Missing ⚠️
...t-controller/commands/applicationset_controller.go	74.83%	28 Missing and 10 partials ⚠️
server/server.go	44.44%	5 Missing ⚠️
cmd/argocd/commands/headless/headless.go	0.00%	4 Missing ⚠️
util/tls/tls.go	0.00%	4 Missing ⚠️
cmd/argocd/commands/admin/cluster.go	0.00%	2 Missing ⚠️
reposerver/gpgwatcher.go	0.00%	2 Missing ⚠️
util/cache/cache.go	96.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #19003      +/-   ##
==========================================
- Coverage   50.65%   50.64%   -0.01%     
==========================================
  Files         315      315              
  Lines       43286    43260      -26     
==========================================
- Hits        21926    21911      -15     
+ Misses      18861    18846      -15     
- Partials     2499     2503       +4     

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[rumstead]

This was added to make sure the argocd processes would shut down gracefully and have the golang coverage from the e2e "flushed" to the files. We should just confirm that test-containers send the proper signals to cause the flush to happen.

(Just commenting about the contributors meeting today as a reminder :))