Preflight Permission Check for Excessive Permission

[bentito]

Similar to #988, this issue proposes a security-minded preflight permission check that warns when the referenced Service Account is granting more permission than needed for a Cluster Extension to do its work.

Currently, Cluster Extension installations can proceed even if the provided Service Account has excessive permissions. A preflight check would help ensure that Cluster Extensions operate within the principle of least privilege, enhancing the overall security of the cluster.

• This proposal builds upon previous efforts to define and manage Service Account permissions within Cluster Extensions:

• A preflight check that analyzes Service Account permissions and flags potential over-privileging would significantly contribute to a more secure Cluster Extension deployment process.