Get namespaced Identities from Yral-Auth

[ravi-sawlani-yral]

Motivation

Generate namespaced identities from base identities by appending namespace string to the private seed.

For now namespace would be given in a jwt token signed by backend admin key

For backwards compatibility for already generated yral identities check if there is a canister in yral metadata with base identities if so return that for yral identities

[ravi-sawlani-yral]

Duplicate of #1