#484 Add GSClient timeout support

[Mchristos]

Adds GSClient option to include a timeout in seconds. When using google.cloud.storage, it's possible to manually increase the timeout from the default of 60 seconds, but with cloudpathlib it's not possible to tweak this. This makes, for example, uploading larger files with slow internet connection impossible to achieve using cloudpathlib

Closes #484

---

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• I have read and understood CONTRIBUTING.md
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• Confirmed PR is rebased onto the latest base
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Usage:

from cloudpathlib import CloudPath, GSClient
client = GSClient(timeout=.00001)
with CloudPath("gs://path/to/test_file.txt", client=client).open("wb") as f:
    f.write(os.urandom(10000000))
# Raises Timeout Error

[pjbull]

Thanks @Mchristos! Code looks reasonable, but I was wondering if there are other kwargs that are either shared or that we should accept as upload_kwargs and download_kwargs to the client and use in the respective methods so that we can support all of the potential kwargs. Would you mind checking the SDK and seeing what makes sense?

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 93.2%. Comparing base (7f1a5dc) to head (9b034b7).

Files with missing lines	Patch %	Lines
cloudpathlib/gs/gsclient.py	85.7%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           master    #485     +/-   ##
========================================
- Coverage    94.4%   93.2%   -1.3%     
========================================
  Files          23      23             
  Lines        1776    1780      +4     
========================================
- Hits         1678    1659     -19     
- Misses         98     121     +23     

Files with missing lines	Coverage Δ
cloudpathlib/gs/gsclient.py	89.6% <85.7%> (-1.9%)	⬇️

... and 2 files with indirect coverage changes