Add annotations to upgradeCheck ConfigMap

What does this MR do?

Adds the possibility to configure annotations for the upgradeCheck configMap. We deploy GitLab with ArgoCD and need to set some annotations specifically on the ConfigMap to ignore detected differences. Using a dedicated <kubernetes-kind>Annotations value is already done in e.g. the MinIO chart, so I decided to create a new ConfigMapAnnotations value, to not risk any side effects when reusing the already existing upgradeCheck.annotations.

Related issues

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

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
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated (didn't find any documentation referencing the upgradeCheck values
• Tests added (didn't find any existing tests that I could extend/upgrade)
• Integration tests added to GitLab QA (didn't find any existing tests that I could extend/upgrade)
• Equivalent MR/issue for omnibus-gitlab opened (not required)
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file. (not really feasible)