feat: add possibility to initialize client by json file

[bednar]

Closes #444

Proposed Changes

Added possibility to initialize client by json file.

The format of the json file is same as is produced by influx config:

influx config --json

{
        "url": "http://localhost:8086",
        "token": "my-token",
        "org": "my-org",
        "active": true
}

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• pytest tests completes successfully
• Commit messages are conventional
• Sign CLA (if not already signed)

[codecov-commenter]

Codecov Report

Merging #467 (49ec9b6) into master (161e202) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #467      +/-   ##
==========================================
+ Coverage   89.45%   89.50%   +0.04%     
==========================================
  Files          38       38              
  Lines        3292     3306      +14     
==========================================
+ Hits         2945     2959      +14     
  Misses        347      347              

Impacted Files	Coverage Δ
influxdb_client/client/influxdb_client.py	98.73% <ø> (ø)
influxdb_client/client/influxdb_client_async.py	91.37% <ø> (ø)
influxdb_client/client/_base.py	97.93% <100.00%> (+0.08%)	⬆️

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[powersj]

Thanks for this!