Remove shared-secrets chart and move templates to root

What does this MR do?

Remove the shared-secrets chart. Move the job, configmap, RBAC templates and other helper templates to the root Chart. This gives shared-secrets chart access to ALL the variables and we won't have to put things under global just for shared-secrets job to access them.

Summary of changes made

1. Rename all the templates to have a shared-secrets- prefix, and put them in the root templates/ directory.
2. Create shared-secrets.fullname and shared-secrets.name templates to match what was existing, and use them instead of fullname and name templates in cnofigmaps/jobs/rbac etc. This was done to minimize changes.
3. Use $sharedSecretValues := index .Values "shared-secrets" to collect all the shared-secrets values (Damn you, hyphen) and use them instead of .Values.. (Except when .Values.global is being used
4. Rename _shared-secrets-generate_secrets.sh to _shared-secrets-generate_secrets.sh.tpl so as to make helm lint happy. Syntax highlighting, at least for vim, is fixed by using a modline.

Related issues

Closes #1971 (closed)

Checklist

See Definition of done.

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Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened