fix: deep evaluate matrix strategy (#964)

* fix: deep evaluate matrix strategy

* Try to make linter happy.

* Apply PR feedback, fix insert directive more tests

* Fix: logic error

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

pkg/runner/testdata/evalmatrix-merge-map/push.yml

@@ -0,0 +1,14 @@
+on: push
+jobs:
+  a:
+    strategy:
+      matrix:
+        a:
+        - env:
+              key1: val1
+              ${{insert}}:
+                 key2: val2
+              ${{ insert }}: ${{fromJSON('{"key3":"val3"}')}}
+    runs-on: ubuntu-latest
+    steps:
+    - run: exit ${{ (matrix.a.env.key2 == 'val2' && matrix.a.env.key1 == 'val1' && matrix.a.env.key3 == 'val3' ) && '0' || '1' }}