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>

pkg/runner/step_action_local_test.go

@@ -275,6 +275,7 @@ func TestStepActionLocalPost(t *testing.T) {
 				Step:   tt.stepModel,
 				action: tt.actionModel,
 			}
+			sal.RunContext.ExprEval = sal.RunContext.NewExpressionEvaluator(ctx)
 
 			if tt.mocks.env {
 				cm.On("UpdateFromImageEnv", &sal.env).Return(func(ctx context.Context) error { return nil })