Update Flight proto

[Jefffrey]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

From mailing list: https://lists.apache.org/thread/4t664cj5z52brmbshjb6gknfq30ckhcn

Now, here lies the issue: neither FlightEndpoint nor the FlightInfo message in the arrow.flight.protocol.rs file of arrow-rs includes an 'app_metadata' field (It seems outdated). Consequently, I am currently facing a roadblock.
Is there a plan to update the flight implementation of arrow-rs?

Need to update the Flight & FlightSql proto as they are outdated.

See arrow source:

• https://github.com/apache/arrow/blob/0993b369c4b91d81a17166d1427e7c26cd9beee4/format/Flight.proto
• https://github.com/apache/arrow/blob/0993b369c4b91d81a17166d1427e7c26cd9beee4/format/FlightSql.proto

Describe the solution you'd like

Update format files and generated code (and interop code, refer to PR below for previous example)

Describe alternatives you've considered

Additional context

For reference, last update PR: #4250

[Jefffrey]

I can take a stab at this next week or so, unless someone else is interested in picking this up 👀

[tustvold]

label_issue.py automatically added labels {'arrow'} from #5413

[tustvold]

label_issue.py automatically added labels {'arrow-flight'} from #5413