[bug] global_settings order of preference.

[nusrath432]

Describe the bug
When defining global_settings block for a given landingzone, the current landingzone should take precedence over global_settings defined in lower/other current landingzones. Also, the global_settings should only be imported when global_settings_key is defined. Since a merge function is used, the order of items in the map is important.

To Reproduce
Steps to reproduce the behaviour:
Create a landingzone with global_settings [passthrough = true;]
Create another landingzone with global_settings [passthrough = false; prefix=xyz]
Now within the landingzone.tfvars, reference the 1st landingzone within the tfstate block.

Expected behavior
passthrough = false, prefix = xyz should take preference and the resources should not be destroy by referencing to lower tfstate.

Pull Request
[Global_settings precedence] #448

[nusrath432]

Note: Until this issue is addressed, as a work around, we can define the following block, to override the lower level passthrough=true

custom_variables = {
  passthrough = false
}

This way, the resources will not be destroyed when we reference lower level TF state file.

Remember we have to override not just passthrough but all those values that cause a difference between global_settings {} vs custom_variables {} blocks. For example: prefixes, random_length etc

[nusrath432]

@arnaudlh @LaurentLesle Could you share your thoughts on this issue please

Do we have any Roadmap or Project board for this project to track - it is a while since we had any new release.