Add a framework, fixtures and test for common synchronize scenarios. (#15983)

* Add a framework, fixtures and test for common synchronize scenarios.

Addresses #15905

test/units/plugins/action/fixtures/synchronize/basic_become/meta.yaml

@@ -0,0 +1,38 @@
+task_args:
+    src: /tmp/deleteme
+    dest: /tmp/deleteme
+    #rsync_path: rsync
+_task:
+    become: True
+    become_method: None
+fixtures:
+    taskvars_in: task_vars_in.json
+    taskvars_out: task_vars_out.json
+connection:
+    transport: 'ssh'
+_play_context:
+    become: True
+    become_method: sudo
+    remote_addr: el6host
+    remote_user: root
+hostvars:
+    '127.0.0.1': {}
+    '::1': {}
+    'localhost': {}
+asserts:
+    - "hasattr(SAM._connection, 'ismock')"
+    - "SAM._connection.transport == 'local'"
+    - "self.execute_called"
+    - "self.task.args['_local_rsync_path'] == 'rsync'"
+    # this is a crucial aspect of this scenario ...
+    - "self.task.args['rsync_path'] == '\"sudo rsync\"'"
+    - "self.task.args['src'] == '/tmp/deleteme'"
+    - "self.task.args['dest'] == 'root@el6host:/tmp/deleteme'"
+    - "self.task.become == True"
+    - "self.task.become_user == None"
+    - "self._play_context.shell == 'sh'"
+    - "self._play_context.remote_addr == 'el6host'"
+    - "self._play_context.remote_user == 'root'"
+    - "self._play_context.become == False"
+    - "self._play_context.become_user == 'root'"
+    - "self._play_context.password == None"