arrow

GH-43258: [C++][Flight] Use a Base CRTP type for the types used in RPC calls (#43255)

### Rationale for this change

Flight should eventually be buildable without a specific protobuf version. As such, all the protobuf types are wrapped in hand-written classes. Uniformity of the interface is not enforced even though it's desirable. Extending the interface requires adding functions to every struct. A common base class can mitigates risks and reduce the amount of hand-written code.

### What changes are included in this PR?

 - Definition of a BaseType<> template (a CRTP)
 - Add constructors that aren't implicitly defined anymore
 - Having a default value for some fields that would be undefined values otherwise
 - Leverage this structure to add `SerializeToBuffer` to all the types
 - ~30KiB in binary size reduction 
 
### Are these changes tested?

By existing tests.
* GitHub Issue: #43258

Authored-by: Felipe Oliveira Carvalho <felipekde@gmail.com>
Signed-off-by: Felipe Oliveira Carvalho <felipekde@gmail.com>