Remove registry usage from Key Stores Management in IS

[UdeshAthukorala]

Is your feature request related to a problem? Please describe. The key Stores of the Identity Server currently uses the Registry as its storage repository, which is a roadblock to the plan to remove the Registry from the Identity Server.

This is part of the larger effort to remove the Registry from the Identity Server, which will help lower operational and product maintenance costs.

Describe the solution you would prefer Need to find an alternative solution for managing Key Stores that doesn’t depend on the Registry.

This issue will track the progress of the registry usage removal from the Key Stores.

Additional context Registry removal parent issue,

• https://github.com/wso2/product-is/issues/20001

Previous effort on the same effort has done with,

• https://github.com/wso2/product-is/issues/16422