Arrow flight examples don't compile

[codonnell]

Describe the bug

There is an API incompatibility between tonic 0.10 and 0.11. We have 0.10 as a transitive dependency of arrow-flight, and datafusion-examples pulls in 0.11 directly. As a result the flight examples won't compile.

It's also not possible to run nested examples with cargo run --example, so these examples cannot be run at the moment.

To Reproduce

Add an explicit example block like below to the datafusion-examples Cargo.toml:

[[example]]
name = "flight_sql_server"
path = "examples/flight/flight_sql_server.rs"

and run cargo run --example flight_sql_server. You should see compilation errors arising from a couple of tonic structs that were moved into a new module.

Expected behavior

The arrow flight examples should be runnable and should compile.

Additional context

No response