feat: Support alias for helm repo in application source

[OpenGuidou]

Closes #17621

In terms of user experience, reusing the name we've defined in the repositories (and most probably shorter than the URL) would be better. I'm proposing here to reuse the helm alias syntax.

It also allows to have a single Application definition that can be reused in different environments (different repoURL/authentication, under the same repo name) if using separated repo and ArgoCD instances.

Checklist:

• [x] 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.
• [x] The title of the PR states what changed and the related issues number (used for the release note).
• [x] The title of the PR conforms to the Toolchain Guide
• [x] I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• [x] I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• [x] Does this PR require documentation updates?
• [x] I've updated documentation as required by this PR.
• [x] I have signed off all my commits as required by DCO
• [x] I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• [x] My build is green (troubleshooting builds).
• [x] My new feature complies with the feature status guidelines.
• [x] I have added a brief description of why this PR is necessary and/or what this PR solves.
• [x] Optional. My organization is added to USERS.md.
• [x] 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).

[speedfl]

Look good to me. I will take one last look when tests are fixed, For the e2e you need to change the name of your tests. They are used to build the helm release name. It exceeds the 53 chars. Another solution would be to allow to set the release name but this represents more code

[speedfl]

Would need a code owner approval

[blakepettersson]

@OpenGuidou there are some conflicts now which needs to be resolved

[OpenGuidou]

@OpenGuidou there are some conflicts now which needs to be resolved

@blakepettersson Done now !

[OpenGuidou]

Hi @argoproj/argocd-approvers ,

Could I get a review on this one ?

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 91.66667% with 10 lines in your changes missing coverage. Please review.

Project coverage is 50.73%. Comparing base (7af5793) to head (1905914).

Files	Patch %	Lines
server/repository/repository.go	83.33%	4 Missing and 1 partial :warning:
server/application/application.go	87.50%	2 Missing and 2 partials :warning:
reposerver/repository/repository.go	98.03%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #17840      +/-   ##
==========================================
+ Coverage   50.65%   50.73%   +0.07%     
==========================================
  Files         315      316       +1     
  Lines       43344    43415      +71     
==========================================
+ Hits        21958    22027      +69     
- Misses      18880    18884       +4     
+ Partials     2506     2504       -2     

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[OpenGuidou]

Hi @blakepettersson , @argoproj/argocd-approvers , @argoproj/argocd-approvers-docs Can I get a review ?