arrow

ARROW-15067: [C++] Add tracing spans to the scanner

Continuing https://github.com/apache/arrow/pull/12328 and https://github.com/apache/arrow/pull/11964.
The tracing spans were not propagated through all the asynchronous constructs, causing some spans to become disconnected from the trace. This PR aims to address this.
Some things left to do:
- [x] Possibly add some attributes to the `read_column` span
- [x] fix parent/sibling relationships (some of the new spans should probably become a child)
- [x] Do something about all the `#ifdefs`
- [x] Wrap around a `Future`
- [x] Wrap `Executor`
- [x] Check if tracing now works properly for all of the file types, not just parquet
- [x] lidavidm mentioned some memory leaks that should be investigated
- [x] The `FragmentToBatches` span seems to be active way too long

Closes #12609 from joosthooz/arrow-15067

Lead-authored-by: Joost Hoozemans <joosthooz@msn.com>
Co-authored-by: David Li <li.davidm96@gmail.com>
Co-authored-by: Matthijs Brobbel <m1brobbel@gmail.com>
Signed-off-by: David Li <li.davidm96@gmail.com>