Add ArgumentAction.ACTION, support POSIX bundling in CAP, Move all Actions to their own file

tests/test_parsers/test_argument_action.py

@@ -0,0 +1,11 @@
+from falyx.parsers import ArgumentAction
+
+
+def test_argument_action():
+    action = ArgumentAction.APPEND
+    assert action == ArgumentAction.APPEND
+    assert action != ArgumentAction.STORE
+    assert action != "invalid_action"
+    assert action.value == "append"
+    assert str(action) == "append"
+    assert len(ArgumentAction.choices()) == 8