General MR

Summary

With these changes, manual intervention from an engineer is only required when the upstream Deployment has a change.

A new update-mattermost-operator-templates script was added to renovate-runner to automate the manual steps of updating this chart from upstream. The script downloads the upstream manifests and disseminates them to the proper locations within our chart. Our custom labels are added to each resource. Since deployment.yaml is the only file with manual changes, we overwrite it only when there's a change to it in the upstream manifests, and it's written with a fail statement at the top reminding the engineer to manually propagate those changes. See the screenshots for an example.
The templates from upstream were relocated to templates/upstream to make this automation easier.
The crds were consolidated in a single crds.yaml.