Allow users to configure Cluster Agent Priority Classes And Pod Disruption Budgets on rke2 and k3s clusters

[eva-vashkevich]

RFC: Cluster Agent Priority Classes And Pod Disruption Budgets
JIRA: SURE-9007, SURE-8174

This feature will only be supported for node-driver provisioned and custom rke2/k3s clusters and generic imported clusters.

Please refer to the RFC for UI spec: RFC-22

[richard-cox]

@eva-vashkevich Might have brought this up elsewhere, but might sure to review the description once / if the RFC is approved by the RATs team

[yonasberhe23]

Requires manual validation.