fix!: change the default cluster issuer, remove the namespace variable, hardcode the Helm release name, add workload identity support

[lentidas]

Description of the changes

The main changes of this PR are the following:

• fix!: hardcode the release name to remove the destination cluster

  I found out that Argo CD passes the name of the application as a value to set the Helm chart. This means that all the templating that used { $.Release.Name } would resolve to the name given to Argo CD application.

  In a multicluster deployment, using a single Argo CD, the names of the applications must be different. We solved that by appending the cluster name to the default application name when deploying on different clusters than in-cluster. However, this resulted in multiple problems for deployments that depended on the name of the application being static, so this solves that.

  This is a breaking change because sometimes this requires an application to be deleted and recreated.

• fix!: remove the namespace variable

  We found out that on multiple modules we were referencing resources from other modules using their default namespaces and this was hardcoded. In case someone decided to change the namespace of deployment of a certain application, this could break the way modules work with each other.

  We've decided that in order to avoid undefined behaviors caused by overloading this variable, it would be best to remove it entirely.

• fix!: remove the ArgoCD namespace variable

  Since we are hardcoding the namespace variable on all modules, the variable to set the ArgoCD namespace will no longer be needed as well.

• feat(aks): add support to use workload identity for storage auth

  This requires a chart version bump to at least v12.16.2. This will be done with a different PR.

• Change the default cluster issuer to the one that is in fact always created by the cert-manager module.

⚠️ Do a Rebase and merge

Breaking change

• Yes (in the module itself): because of the removal of the namespace and argocd_namespace variables and the fact that overloading the release name can force a recreation of the application.

Tests executed on which distribution(s)

• AKS (Azure)
• EKS (AWS)
• SKS (Exoscale)