[C++][Python][FlightRPC] Add Flight SQL ADBC driver and Python bindings

[asfimport]

Pending ADBC acceptance.

This will finally make Flight SQL accessible in Python, though it will rely on having the ADBC driver manager available to provide the Python bindings.

Reporter: David Li / @lidavidm
Assignee: David Li / @lidavidm

Related issues:

• [C++] Native database interfaces (relates to)

PRs and other links:

• GitHub Pull Request #14082

_{Note: This issue was originally created as ARROW-17661. Please see the migration documentation for further details.}

[lidavidm]

I'm going to cancel this since it seems getting it packaged will be too difficult and we can ship the Go Flight SQL driver in a wheel instead.