Move unary kernels to arrow-array (#2787)

[tustvold]

Which issue does this PR close?

Part of #2787

Rationale for this change

See ticket

What changes are included in this PR?

Moves the unary kernel implementation to arrow-array

Interestingly this actually improves performance for a number of the kernels, even those that don't use unary. My only guess is that by better distributing the codegen, LLVM better optimises the resulting code.

Are there any user-facing changes?

No

[viirya]

Looks good. I saw you mentioned binary and try_binary kernels too in the ticket but not in the change here. Will you move them too?

[tustvold]

I saw you mentioned binary and try_binary kernels too in the ticket but not in the change here

I need to think a bit more on this, I don't have an immediate need for them just yet, and I would need to move some functions like combine_option_bitmap.

[ursabot]

Benchmark runs are scheduled for baseline = 333633e and contender = 2ba1307. 2ba1307 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java