ARROW-11420: [Rust] Added support to length of Binary and List.

[jorgecarleitao]

This adds [Large]Binary and [Large]List support to length.

Also removes unneeded unsafe enabled by the recent PR #9215.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-11420

[codecov-io]

Codecov Report

Merging #9353 (48d78ca) into master (2fd5857) will decrease coverage by 0.02%.
The diff coverage is 74.54%.

@@ Coverage Diff @@## master #9353 +/- ##
==========================================
- Coverage 81.97% 81.95% -0.03% 
==========================================
Files 216 216 Lines 53227 53270 +43 ==========================================
+ Hits 43633 43657 +24 - Misses 9594 9613 +19 

Impacted Files	Coverage Δ
rust/datafusion/src/physical_plan/functions.rs	71.80% <55.55%> (-0.50%)	⬇️
rust/arrow/src/compute/kernels/length.rs	88.61% <78.26%> (-11.39%)	⬇️
rust/parquet/src/encodings/encoding.rs	94.86% <0.00%> (-0.20%)	⬇️

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[alamb]

looks really nice @jorgecarleitao 👍

[alamb]

@jorgecarleitao -- this one needs a rebase and then I think it is ready to go

[nevi-me]

.null_buffer().cloned() ?

[alamb]

I went through this again. I think it is good -- is there anything else you want to add @jorgecarleitao (tests? ) or shall we merge it?

[alamb]

@jorgecarleitao I think this one is ready to go -- it just needs a rebase and then merge

[alamb]

The Apache Arrow Rust community is moving the Rust implementation into its own dedicated github repositories arrow-rs and arrow-datafusion. It is likely we will not merge this PR into this repository

Please see the mailing-list thread for more details

We expect the process to take a few days and will follow up with a migration plan for the in-flight PRs.