Replace flatbuffers dependency by Planus

[jorgecarleitao]

This PR will stay here for some time. It replaces the flatbuffers crate by planus, a recently released replacement to flatbuffers. See #725 for details.

This switches one for the other. All tests and integration tests pass, showing that it does indeed work as advertised 💯

[codecov]

Codecov Report

Merging #732 (f64209d) into main (276d670) will increase coverage by 0.09%.
The diff coverage is 84.03%.

@@            Coverage Diff             @@
##             main     #732      +/-   ##
==========================================
+ Coverage   71.02%   71.11%   +0.09%     
==========================================
  Files         315      316       +1     
  Lines       16950    16782     -168     
==========================================
- Hits        12038    11934     -104     
+ Misses       4912     4848      -64     

Impacted Files	Coverage Δ
src/ffi/ffi.rs	83.67% <ø> (ø)
src/io/flight/mod.rs	0.00% <0.00%> (ø)
src/io/ipc/compression.rs	92.85% <ø> (ø)
src/io/ipc/mod.rs	0.00% <0.00%> (ø)
src/io/ipc/read/array/binary.rs	43.24% <ø> (+2.70%)	⬆️
src/io/ipc/read/array/boolean.rs	44.44% <ø> (+3.70%)	⬆️
src/io/ipc/read/array/dictionary.rs	47.61% <ø> (ø)
src/io/ipc/read/array/fixed_size_binary.rs	44.44% <ø> (+3.70%)	⬆️
src/io/ipc/read/array/fixed_size_list.rs	40.00% <ø> (ø)
src/io/ipc/read/array/list.rs	25.64% <ø> (+2.56%)	⬆️
... and 31 more

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[jorgecarleitao]

Added MIRI check to a round-trip over IPC. All still green.

[jorgecarleitao]

I though that this would take longer, but it is essentially done: tests pass, MIRI checks pass, simpler to use and a safer design.

One step missing is benchmarks of read and write, to check if there is no major regression.

@sundy-li , @ritchie46 , @houqp, @yjshen , any thoughts on this?

My opinion is that flatbuffers is unmaintained and has soundness issues, which is a concern because IO is an obvious attack vector - it does not mean that planus won't become unmaintained (maybe @TethysSvensson or @kristoff3r could chip in here wrt to their plans?).

[TethysSvensson]

@jorgecarleitao While I am not going to give any guarantees (this being a hobby, open source project after all), my current plan is to maintain and improve upon the library for at least the next year, since we are planning to use the library in product at skybox.gg.

What happens after that is too far into the future for me to predict and also depends on whether there is any community adoption.