Create a deepcopy of config when creating workspace client from account client

[kartikgupta-db]

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

[codecov-commenter]

Codecov Report

Attention: 7 lines in your changes are missing coverage. Please review.

Comparison is base (a1055d1) 57.89% compared to head (914f32e) 57.92%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
databricks/sdk/__init__.py	25.00%	3 Missing ⚠️
databricks/sdk/core.py	81.81%	2 Missing ⚠️
databricks/sdk/casing.py	95.83%	1 Missing ⚠️
databricks/sdk/config.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #542      +/-   ##
==========================================
+ Coverage   57.89%   57.92%   +0.03%     
==========================================
  Files          44       45       +1     
  Lines       27956    27990      +34     
==========================================
+ Hits        16185    16214      +29     
- Misses      11771    11776       +5     

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[edwardfeng-db]

Thanks @kartikgupta-db