Argo-cd: /api/version reports helm version from something other than `argocd-repo-server`

[jsoref]

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Checklist:

• [x] I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
• [x] I've included steps to reproduce the bug.
• [x] I've pasted the output of argocd version.

Describe the bug

/api/version reports the version from argocd-server instead of argocd-repo-server

To Reproduce

1. Use a baseline version of argocd with helm 3.2.0

2. In the chart, update the helm version to 3.3.1 but only for repoServer (based on https://argoproj.github.io/argo-cd/operator-manual/custom_tools/#adding-tools-via-volume-mounts):

     repoServer:
       env:
         - name: ARGOCD_EXEC_TIMEOUT
           value: 3m
       # From: https://github.com/EarnestResearch/dhall-packages/blob/master/kubernetes/argocd/kustomize/overlays/argocd-repo-server-deployment.yaml
       volumes:
         - name: tools
           emptyDir: {}
       initContainers:
         - name: download-helm
           image: alpine:3.8
           command:
             - sh
             - -c
           args:
             - wget -qO- https://get.helm.sh/helm-v3.3.1-linux-amd64.tar.gz | tar -xzf - linux-amd64/helm && cp linux-amd64/helm tools/helm
           volumeMounts:
             - mountPath: /tools
               name: tools
       volumeMounts:
         - mountPath: /usr/local/bin/helm
           name: tools
           subPath: helm
   

3. visit /api/version in your web browser, e.g. https://cd.apps.argoproj.io/api/version

Expected behavior

The helm version should be the version from argocd-repo-server not the version from argocd-server (I'm pretty sure this is the version that's being reported)
This is based on the descriptions in https://argoproj.github.io/argo-cd/operator-manual/high_availability/#argocd-repo-server

I mentioned this in https://github.com/argoproj/argo-cd/issues/4312#issuecomment-692903775

Screenshots

Version

(This actually matters a lot, but my cluster is busy making a mess / upgrading stuff, so I don't have the pieces handy)

Logs

Paste any relevant application logs here.

[jessesuen]

Repo server should expose a version endpoint containing the tooling version and argocd version should make a call to the repo server to report version.

[jessesuen]

Lets also add query parameters to control what information is returned since to avoid hard dependency on repo-server