If overridden file exists, then process it and find the missing key values from base file.

[thavaahariharangit]

What are you trying to accomplish?

When the config file is overridden, the code should process it and find the missing key values from the base file.

Anything you want to highlight for special attention from reviewers?

Ref : https://developer.hashicorp.com/terraform/language/files/override

How will you know you've accomplished your goal?

Wrote an rspec test to check if the overridden module does not include the source. And ensured that when there is a property present in both then overridden value is present in the dependency set.

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.

[abdulapopoola]

As a follow up; can we add Sorbet typing to this file please?