Split core tooling to core and workloads

[mjudeikis]

As the Kubernetes Resource Model (KRM) moves beyond Workloads, we already have a few examples of APIServer being used without workload capabilities (or with partial capabilities).

vCluster - no functional nodes as such, just pods
shootless Gardener - no nodes
Generic Control Plane (https://github.com/kcp-dev/generic-controlplane) No pods and Nodes
kcp (kcp.io) -multi-tenant control planes (no pods and nodes).
In general, with kubernetes/enhancements#4080 merged, one can construct Kubernetes-like APIs without Nodes or pods or even other apis.

Now AI comes into the room:
core toolset in the current form includes pods and nodes, which might not be available when using this MCP server with a workloadless api server.

Proposal would be to split core into core and workloads, where pods, nodes would get their own tooling set (with more workloads-related tools to be added potentially). It would be enabled by default (same as core), leaving core - generic api operations only.

The alternative now is to enable core and use disabled_tools config to disable workload-related tools.

In general, I don't think duplicating tools within the toolset is appropriate, so making the toolset more granular might be a better option.