Introduce wg_tags to handle default_tags on provider level

[kbcz1989]

PR o'clock

closes: #1578, #1455(?), #1248(?)

Description

When default_tags are used on aws provider level, and the same tags are defined as input to this module, we end up with this issue:
default_tags always shows an update

If "tags" var is not set, no tags will be applied to resources which defines tag_specification.

So, either we have default_tags and do not set "tags". which leaves us with "empty" tag_specifications or we don't use default_tags.

This PR introduces new variable "wg_tags", which will be used on resources which define dynamic tags/tag_specifications if "tags" is not set. Backward compatibility is therefore fully retained.

There will be changes only if wg_tags is set, otherwise the module works the same as before.

Checklist

• README.md has been updated after any changes to variables and outputs. See https://github.com/terraform-aws-modules/terraform-aws-eks/#doc-generation

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues. If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.