outofband/actions: rework transitions

- Group stateswitch.Transition and related types into the internal Transition type
In thier original form the stateswitch.Transition types were disjoint and
were declared all over the place. This adds the internal Transition type
which groups together the Transition state, handler, docs and related
objects.

- Generate Transitions from bmclib FirmwareInstallSteps
Since BMCs have varying ordering, requirements for a firmware install process,
we let bmclib tell us how a firmware install should be performed through
the bmclib.FirmwareInstallSteps() method and order the Transitions
based on FirmwareInstallSteps()

Makefile

@@ -13,13 +13,17 @@ REPO := "https://github.com/metal-toolbox/flasher.git"
 .DEFAULT_GOAL := help
 
 ## lint
-lint:
+lint: gen-mock
 	golangci-lint run --config .golangci.yml
 
 ## Go test
-test:
+test: lint
 	CGO_ENABLED=0 go test -timeout 1m -v -covermode=atomic ./...
 
+## Generate mocks
+gen-mock:
+	mockgen -source internal/model/model.go -destination internal/fixtures/mock.go -package fixtures
+
 ## build-osx
 build-osx:
 ifeq ($(GO_VERSION), 0)