fix: Accept nested quotes within strings

[mutahhir]

Related issue

Fixes https://github.com/orgs/hashicorp/projects/207/views/12?pane=issue&itemId=25824299

Description

If strings to be converted have quotes nested within them, we throw an error here. I don't know where we should solve this problem, but it requires more than just a few regexs. I went for a really complex solution but it just doesn't work without parsing. Maybe I missed something, but I'd like to get the core fix out before we find a complete solution to strings with nested quotes and nested templates.

Checklist

• I have updated the PR title to match CDKTF's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works if applicable
• New and existing unit tests pass locally with my changes

[team-tf-cdk]

This PR exceeds the recommended size of 1000 lines. Please make sure you are NOT addressing multiple issues with one PR. Note this PR might be rejected due to its size.

[github-actions]

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