state: remove FromParams helper

`FromParams` forces `state` to depend on `apiserver/params` for its input parameters.

Ideally params should own these helpers, but that would require it to depend on state, which would currently cause an import loop.

Instead move the function to the calling packages temporarily.
Merge pull request #765 from davecheney/201-state-machine-remove-from-params

state: remove MachineJobFromParams helper

`MachineJobFromParams` forces `state` to depend on `apiserver/params` for its input parameters.

Ideally params should own these helpers, but that would require it to depend on state, which would currently cause an import loop.

Instead move the function to the calling packages temporarily.