Create a deepcopy of config when creating workspace client from account client (#542)

## Changes
* We are creating a shallow copy of the config object when creating a ws
client from acc client. This leads to the config of acc client being
overridden by changes made for the workspace client. This PR makes it so
that we are making a deepcopy instead.
* Also, correctly handle list response jsons in the API client. 

## Tests
* added integration test

- [ ] `make test` run locally
- [ ] `make fmt` applied
- [ ] relevant integration tests applied

Author: kartikgupta-db

databricks/sdk/__init__.py

@@ -457,3 +457,8 @@ def copy(self):
         cpy: Config = copy.copy(self)
         cpy._user_agent_other_info = copy.deepcopy(self._user_agent_other_info)
         return cpy
+
+    def deep_copy(self):
+        """Creates a deep copy of the config object.
+        """
+        return copy.deepcopy(self)

databricks/sdk/config.py

@@ -142,7 +142,12 @@ def do(self,
             resp[header] = response.headers.get(Casing.to_header_case(header))
         if not len(response.content):
             return resp
-        return {**resp, **response.json()}
+
+        json = response.json()
+        if isinstance(json, list):
+            return json
+
+        return {**resp, **json}
 
     @staticmethod
     def _is_retryable(err: BaseException) -> Optional[str]:

databricks/sdk/core.py

@@ -14,3 +14,13 @@ def test_get_workspace_client(a):
 def test_get_workspace_id(ucws, env_or_skip):
     ws_id = int(env_or_skip('THIS_WORKSPACE_ID'))
     assert ucws.get_workspace_id() == ws_id
+
+
+def test_creating_ws_client_from_ac_client_does_not_override_config(a):
+    wss = list(a.workspaces.list())
+    if len(wss) == 0:
+        pytest.skip("no workspaces")
+    a.get_workspace_client(wss[0])
+
+    # assert doesn't throw
+    wss = list(a.workspaces.list())