Refactor Helm templates to configure LDAP/RBAC as OSS, remove Enterprise (v3.4)

[hnanchahal]

Closes #134

[arm4b]

Thanks for the contribution! It's good addition and timing for the v3.4.0 release 👍

I left some first review comments to address below.
Once we'll have a flag to enable/disable rbac, it would be nice to run additional helm install with the rbac enabled (via CircleCI test config).

[arm4b]

Great work, looks good! 👍

I left a few more minor comments.
Would be nice to include in .circleci/config.yml additional scenario for helm upgrade with the st2.rbac.enabled=true to make sure the chart is deployable OK. Here is an example from the history: https://github.com/StackStorm/stackstorm-ha/blob/c2e767cf1cde955237f49afb3a8417c05bdfbb43/.circleci/config.yml#L108-L110

Can you please also resolve merge conflicts and sync with the latest master code?

[arm4b]

@hnanchahal could you please also sync the PR with the upstream (master) changes? That'll resolve git merge conflicts.

[arm4b]

Can we please keep the ongoing development and discussion in the original PR (this one) instead of the new #186?

[arm4b]

It's a pretty big addition and a lot of work.
Many thanks for the contribution! 👍

I've also added Helm Upgrade CI checks with RBAC enabled and included new tests to verify if the RBAC was really loaded and works as part of the normal CI pipeline.