Carbon registry usage removal from the XACML

[darshanasbg]

Is your feature request related to a problem? Please describe.
The XACML feature 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 XACML policies that doesn’t depend on the Registry.

This issue will track the progress of the registry usage removal from the XACML feature.

Additional context
Registry removal parent issue: Remove carbon registry usages in IS

[Niru-D]

Milestones

Milestone 01:

• Create the new table structure.
  • Design doc - https://docs.google.com/document/d/1RCBj2VWnnMBGsXJFDW01ZJx8IhV_rIwahVzNneRIPJ0/edit?usp=sharing

Milestone 02:

• Restructure the source code and create a new DAO layer to access the data.

  • Remove the pluggability of the policy version manager and the policy data store.
    Remove pluggability of version manager and data store in XACML carbon-identity-framework#5681
  • Restructure the code and separate the registry accessing layer into a DAO layer implementing interfaces.
    Add XACML DAO Interfaces carbon-identity-framework#5686
    • Code review - https://drive.google.com/file/d/1s1Jd0woWeFv-sUQb2YeTN2tZ9C8iT88_/view

• Implement the RDBMS extension to the DAO layer.

  • JDBC implementation
    Add XACML DAO JDBC implementation carbon-identity-framework#5776
    • Code review - https://drive.google.com/file/d/1nF701UXbZ-LEYSe4NnP43vZQJDFGqenc/view

• Implement an on-demand migration solution.

Milestone 03:

• Add caching to new DAOs.

Milestone 04:

• Introduce residual migrator.