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GH-36954: [Python] Add more FlightInfo / FlightEndpoint attributes (#43537)

### Rationale for this change
The C++ classes `FlightInfo` and `FlightEndpoint` have attributes that are not available via the Python API.

### What changes are included in this PR?
Make the following attributes available in Python:
- `FlightInfo.ordered`
- `FlightInfo.app_metadata`
- `FlightEndpoint.expiration_time`
- `FlightEndpoint.app_metadata`

Also makes existing attributes optional in constructor:
- `FlightInfo.total_records`
- `FlightInfo.total_bytes`

### Are these changes tested?
Existing tests that test existing attributes are extended.

### Are there any user-facing changes?
Yes, changes are backward compatible.
* GitHub Issue: #36954

Lead-authored-by: Enrico Minack <github@enrico.minack.dev>
Co-authored-by: Adam Reeve <adreeve@gmail.com>
Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>
Co-authored-by: David Li <li.davidm96@gmail.com>
Signed-off-by: David Li <li.davidm96@gmail.com>