feat(frontend): extend message schemas for pow

[DecentAgeCoder]

Motivation

This PR introduces the required schema changes which are used to integrate the pow scheduler used for the 'pow functionality'

Changes

Added new enum values and schema registration for pow protection

Tests

The PR does not provide new tests explicitly, but existing schema and types should align with unit tests if they are already implemented.

[AntonioVentilii]

I think in this particular case, it is better to do this changes together with their usage. For example, if you create a skeleton of the scheduler/worker, or if you develop each message flow in separate PRs

[AntonioVentilii]

Superseded by:

• feat(frontend): implement pow worker and service layer #5887