feat(argo-workflows): Add helper function to determine image value, minus tag (#1754)

We have a situation where we want to exclude the registry so that images can
be pulled from in-network mirrors. Currently when you exclude the registry,
you get stuck with a prefixing forward slash.

Had to keep the tags in the manifest files because helm template requires
a colon in the image value.  Otherwise I'd move it into the helper function.

image entries changed: server, controller, executor

Signed-off-by: jmeridth <jmeridth@gmail.com>

Signed-off-by: jmeridth <jmeridth@gmail.com>

charts/argo-workflows/Chart.yaml

@@ -3,7 +3,7 @@ appVersion: v3.4.4
 name: argo-workflows
 description: A Helm chart for Argo Workflows
 type: application
-version: 0.22.7
+version: 0.22.8
 icon: https://raw.githubusercontent.com/argoproj/argo-workflows/master/docs/assets/argo.png
 home: https://github.com/argoproj/argo-helm
 sources:
@@ -13,4 +13,4 @@ maintainers:
     url: https://argoproj.github.io/
 annotations:
   artifacthub.io/changes: |
-    - "[Added]: Support podGCDeleteDelayDuration and podGCGracePeriodSeconds"
+    - "[Added]: Helm helper function to allow image registry to be absent"