[Feature]: Add ability to import JSON file in App Configuration Store

[gmantri]

Description of the new feature

Currently this feature is available in CLI az appconfig kv import. It would be great if we have the same functionality through Azure PowerShell Cmdlet.

Proposed implementation details (optional)

Same functionality as az appconfig kv import with one additional option to upload from in-memory string type variable holding the configuration data in JSON format.

[isra-fel]

Thanks for reaching out to us. We'll discuss and prioritize the work.