Replaced MutableBuffer by std::Vec

[jorgecarleitao]

This PR replaces

• cache_aligned cargo feature
• the custom implementation of Vec under the feature gate
• the custom allocator
• MutableBuffer

by Rust's std::vec::Vec.

We still need Bytes for the ffi, but this significantly simplifies the APIs for Rust users.

Backward incompatible changes

To migrate:

1. replace Buffer::from(slice) by Buffer::from_slice(slice) (from is now from Vec)
2. replace .from_trusted_len_iter and the like by .extend (since the std lib supports specialization and will pick the trusted len implementation by default)
3. replace MutableBuffer by Vec
4. replace a.extend_constant(additional, value) by a.resize(a.len() + additional, value)

[codecov]

Codecov Report

Merging #693 (7db249a) into main (f64339c) will increase coverage by 0.67%.
The diff coverage is 84.38%.

@@            Coverage Diff             @@
##             main     #693      +/-   ##
==========================================
+ Coverage   69.77%   70.45%   +0.67%     
==========================================
  Files         303      300       -3     
  Lines       16855    16589     -266     
==========================================
- Hits        11761    11688      -73     
+ Misses       5094     4901     -193     

Impacted Files	Coverage Δ
src/array/map/mod.rs	42.62% <0.00%> (ø)
src/compute/sort/mod.rs	26.82% <0.00%> (+0.63%)	⬆️
src/compute/take/list.rs	95.00% <ø> (ø)
src/io/ipc/read/array/binary.rs	48.27% <0.00%> (ø)
src/io/ipc/read/array/list.rs	25.00% <0.00%> (ø)
src/io/ipc/read/array/map.rs	25.00% <0.00%> (ø)
src/io/ipc/read/array/utf8.rs	48.27% <0.00%> (ø)
src/io/parquet/read/binary/basic.rs	68.32% <0.00%> (ø)
src/io/parquet/read/binary/nested.rs	50.00% <ø> (ø)
src/io/parquet/read/binary/utils.rs	100.00% <ø> (ø)
... and 52 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f64339c...7db249a. Read the comment docs.

[ritchie46]

This is awesome! <3

[jorgecarleitao]

@sundy-li , would this be ok for you?

[sundy-li]

That's ok since they have similar pub methods.

Is there any motivation to have MutableBuffer instead of vec at first?

[jorgecarleitao]

MutableBuffer was needed due to the custom allocator aligned to cache lines, under the feature flag cache_aligned. This PR proposes removing the custom allocator (and consequently the MutableBuffer). I never saw any difference between them, and using Vec is safer and much lower maintenance (imo).