Ensure exit_json returns failed = False

This is required for modules that may return a non-zero `rc` value for a
successful run, similar to #24865 for Windows fixing **win_chocolatey**.

We also disable the dependency on `rc` value only, even if `failed` was
set.

Adapted unit and integration tests to the new scheme.
Updated raw, shell, script, expect to take `rc` into account.

test/integration/targets/fetch/tasks/main.yml

@@ -95,7 +95,7 @@
 - name: check fetch directory result
   assert:
     that:
-      - "failed_fetch_dir['failed']"
+      - "failed_fetch_dir|failed"
       - "fetch_dir.msg"
 
 - name: create symlink to a file that we can fetch