Fix Panic on Reading Corrupt Parquet Schema (#2855)

[psvri]

Which issue does this PR close?

Closes #2855.

Rationale for this change

We were accessing the slice without checks and hence panics.

What changes are included in this PR?

Added the check

Are there any user-facing changes?

No

[tustvold]

Could we possibly get a simple unit test of this, e.g. calling get_arrow_schema_from_metadata with an empty string

[ursabot]

Benchmark runs are scheduled for baseline = e1b5657 and contender = 6f8187f. 6f8187f 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