feat: update user-agent and improve transport selection in queryClient

[karel-rehor]

Proposed Changes

1. Updates user-agent value to influxdb3-python/{VERSION}
2. Moves file version.py to directory influxdb_client_3
3. Adds user-agent value to _flight_client. Note that grpc library underlying pyarrow also adds a user-agent header so the two are merged. e.g. ['grpc-c++/1.51.1 grpc-c/29.0.0 (linux; chttp2) influxdb3-python/0.6.0dev0']
4. Tests added for these changes

Checklist

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

[codecov]

Codecov Report

Attention: Patch coverage is 80.61224% with 19 lines in your changes missing coverage. Please review.

Project coverage is 50.52%. Comparing base (933ecb5) to head (8e3197c).

Files	Patch %	Lines
tests/test_query.py	60.00%	18 Missing ⚠️
tests/test_api_client.py	97.56%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##            main      #92       +/-   ##
==========================================
+ Coverage   7.01%   50.52%   +43.51%     
==========================================
  Files         38       39        +1     
  Lines       2196     2276       +80     
==========================================
+ Hits         154     1150      +996     
+ Misses      2042     1126      -916     

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[bednar]

Thank you for your PR! 👍 There is just one requirement that needs to be met before we can merge it into the master branch:

[bednar]

Please simplify this to something like:

Suggested change

	if scheme == 'https':
	self._flight_client = FlightClient(f"grpc+tls://{hostname}:{port}", **self._flight_client_options)
	else:
	self._flight_client = FlightClient(f"grpc+tcp://{hostname}:{port}", **self._flight_client_options)
	if scheme == 'https':
	connectionString = f"grpc+tls://{hostname}:{port}"
	else:
	connectionString = f"grpc+tcp://{hostname}:{port}"
	self._flight_client = FlightClient(connectionString, **self._flight_client_options)

[karel-rehor]

Yes. The connection_string is a better solution. Changed.

[bednar]

LGTM 🚀