Carbon registry usage removal from the Email/SMS templates

[darshanasbg]

Is your feature request related to a problem? Please describe.
Email & SMS templates use registry as its storage repository. Using registry as the data layer, blocks the plan to remove registry from the IS.

Also, the current way of handling the default templates causes the registry database to grow extensively as the number of tenants grows..

Describe the solution you would prefer
Therefore it's needed to remove the registry usages from the Email & SMS templates feature in the IS, improving data model and the way it handles the default templates.

This issue will track the progress of the registry usage removal from the Email/SMS template management feature.

Additional context
Registry removal parent issue,

• Remove carbon registry usages in IS #20001

[nilasini]

@darshanasbg are we good to close this issue with m4? Is there anything pending needs to be done?