[feature request] Add cache for stateutils.GetSandboxState

[AiRanthem]

What would you like to be added:

The function stateutils.GetSandboxState will be called very frequently. Adding a global cache (key+resourceVersion) could significantly improve performance. Considering that memory usage would not be large, this cache can be retained and updated continuously, and only destroyed when a sandbox delete event is detected.

Why is this needed:

[DCchoudhury15]

/assign