fix(terraform): fix variable rendering for foreach resources with dot included names

[gruebel]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

• added a function to join back strings, which were split by a dot and wrongfully applied to dots inside a quoted string, this is happens mainly to a for_each resource key google_project_iam_binding.role["roles/logging.admin"] and results in failing to correctly propagate rendered variables
• I tried it with regex, but couldn't find one, which would do the job for me, so if anyone has a good idea to tackle it more elegant, feel free 🍻

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[SteveVaknin]

Looks good 👍