Add NULL literal support for decimal and integers

[nseekhao]

Modified test

Which issue does this PR close?

Part of #4897

Original PR: datafusion-contrib/datafusion-substrait#40

Rationale for this change

Applying PRs that were already merged in the original repo

What changes are included in this PR?

• Add Substrait producer and consumer support for NULL literals of types:
  • INT8, INT16, INT32
  • DECIMAL128
• Add tests

Are these changes tested?

Yes

Are there any user-facing changes?

No

[andygrove]

Is this clone needed?

[nseekhao]

You're right. The second one is not needed, since we cloned the first one. I also think the second call to register_csv() can just use the default option since we're not using the second table to test Decimals so I'll fix that as well.

[andygrove]

Thanks @nseekhao

[ursabot]

Benchmark runs are scheduled for baseline = 3a1f033 and contender = 7d2318b. 7d2318b 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-datafusion-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-datafusion-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