feat: interpolate the step names (#1422)

* feat: interpolate the step names

Step names could contain expressions refering to event data.

Fixes #1353

* test: add missing mock data

* fix: setup composite expression evaluator

The RunContext does contain a cached ExpressionEvaluator.
This should be the case the composite RunContext as well.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Casey Lee <cplee@nektos.com>

act/runner/job_executor_test.go

@@ -249,7 +249,17 @@ func TestNewJobExecutor(t *testing.T) {
 			sfm := &stepFactoryMock{}
 			rc := &RunContext{
 				JobContainer: &jobContainerMock{},
+				Run: &model.Run{
+					JobID: "test",
+					Workflow: &model.Workflow{
+						Jobs: map[string]*model.Job{
+							"test": {},
+						},
+					},
+				},
+				Config: &Config{},
 			}
+			rc.ExprEval = rc.NewExpressionEvaluator(ctx)
 			executorOrder := make([]string, 0)
 
 			jim.On("steps").Return(tt.steps)