This doesn't actually have a UX to expose this yet - we need to stack a couple of PRs up to get to that.

But this adds plumbing such that we can now stash away a command ID, and retrieve it later as a top-level command. Kinda like pinning for apps, but for anything.

It works off of a new command provider interface ICommandProvider4, which lets us look up CommandItems by ID. If we see a command ID stored in that command provider's settings, we will try to look it up, and then load it from the command provider.

e.g.

    "com.microsoft.cmdpal.builtin.system": {
      "IsEnabled": true,
      "FallbackCommands": {
        "com.microsoft.cmdpal.builtin.system.fallback": {
          "IsEnabled": true,
          "IncludeInGlobalResults": true
        }
      },
      "PinnedCommandIds": [
        "com.microsoft.cmdpal.builtin.system.lock",
        "com.microsoft.cmdpal.builtin.system.restart_shell"
      ]
    },

will get us

Then it's just a matter of plumbing the command provider ID through the layers, so that the command item knows who it is from. We'll need that later for actually wiring this to the command's context menu.

related to #45191
related to #45201