WIP Fixes #47 - support default and custom defined/freeform tags

[jhorwit2]

The tag / value here is based on the aws in-tree provider which tags resources based on the cluster name and whether or not the cluster owns it or not.

[jhorwit2]

So i've modified the original issue to be more generic. Also, the aws cluster pattern isn't supported in OCI because it contains a period, which would act as a namespace and not allowed in freeform tags.

This now supports default defined and freeform tags via an env var OCI_DEFAULT_TAGS. The default tags can be overridden via the oraclecloud.com/additional-tags annotation on the PVC.

The format for both is comma separated list of defined & freeform tags: (namespace\\.)tag_key=value. This matches the style in dynamic group policies and such for using tags.

My thinking is we could use the exact same logic/annotations/env var in other services like the CCM to tag services.

[jhorwit2]

FYI, the e2e tests seem flake kinda often.

[jhorwit2]

@owainlewis thoughts on this implementation?

[owainlewis]

oracle.com/additional-tags would be more consistent here with things like the flex driver e.g. oracle.com/oci as the provisioner name.

[owainlewis]

@jhorwit2 I like the implementation. I would prefer oracle.com/additional-tags for consistency between components. We might want to validate duplicates between default and additional tags at the code level as OCI will fail in the presence of duplicate tag keys.