Refactor local, composite actions and run steps (#712)

Skips docker cp for local actions and use their correct path
Defines GITHUB_ACTION_PATH also for nodejs actions
Evaluate Env of composite action
Evaluate Run of composite action correctly
Evaluate Shell of run step
Evaluate WorkingDirectory of run step
Changed tests for behavior change

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

pkg/runner/testdata/local-action-docker-url/push.yml

@@ -5,4 +5,5 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v2
     - uses: ./actions/docker-url

pkg/runner/testdata/local-action-dockerfile/push.yml

@@ -5,6 +5,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v2
     - uses: ./actions/docker-local
       with:
         who-to-greet: 'Mona the Octocat'

pkg/runner/testdata/local-action-js/push.yml

@@ -5,6 +5,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v2
     - uses: ./actions/node12
       with:
         who-to-greet: 'Mona the Octocat'