Refactor expression evaluator to use parser from actionlint package (#908)

* feat: implement expression evaluator

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>
Co-authored-by: Philipp Hinrichsen <philipp.hinrichsen@new-work.se>

* feat: integrate exprparser into act

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>
Co-authored-by: Philipp Hinrichsen <philipp.hinrichsen@new-work.se>

* Escape { and }, do not fail on missing properties

* Fix empty inputs context

* fix: contains() comparison for complex values

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>
Co-authored-by: Philipp Hinrichsen <philipp.hinrichsen@new-work.se>
Co-authored-by: Christopher Homberger <christopher.homberger@web.de>

pkg/exprparser/testdata/for-hashing-1.txt

@@ -0,0 +1 @@
+Hello

pkg/exprparser/testdata/for-hashing-2.txt

@@ -0,0 +1 @@
+World!