[Modules] New App Configuration Stores module

[ArielRam99]

Description

Creating a new CARML module for app configuration stores. This PR will close out #1368.

@MrMCake @eriqua

Pipeline references

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Pipeline

Type of Change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Checklist

• I'm sure there are no other open Pull Requests for the same update/change
• My corresponding pipelines / checks run clean and green without any errors or warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (readme)
• I did format my code

[eriqua]

Please add a status badge for the corresponding successful pipeline in your fork (Ref https://github.com/Azure/ResourceModules/wiki/Contribution%20guide%20-%20Contribution%20flow#open-a-pr)