[BEAM-11277] Add method to check if two TableSchema are equal

[chunyang]

A followup to #14113 to improve the schema equality checking.

The check in the previous PR has a high false positive rate for detecting whether a schema update job needs to be run because a schema update job is created even if the field ordering is different.

This PR adds a schema equivalence check with more specificity. Now we can do a field-order insensitive comparison on the schema and only run a schema update job when the fields themselves are different.

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Post-Commit Tests Status (on master branch)

Lang	SDK	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go		---	---		---		---
Java
Python		---			---		---
XLang		---			---		---

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website	Whitespace	Typescript
Non-portable
Portable	---		---	---	---	---

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GitHub Actions Tests Status (on master branch)

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[chunyang]

R: @pabloem

Looks like I just missed the closing of the last PR :)

[pabloem]

ooops - sorry about the surprise. I know of someone else making a PR to the same file, so I wanted to avoid merge issues.
I'll take a look at this in a bit.

[codecov]

Codecov Report

Merging #14394 (abbf09e) into master (93a6927) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@ Coverage Diff @@## master #14394 +/- ##
==========================================
- Coverage 83.45% 83.44% -0.02% 
==========================================
Files 470 470 Lines 59001 59100 +99 ==========================================
+ Hits 49239 49315 +76 - Misses 9762 9785 +23 

Impacted Files	Coverage Δ
...s/python/apache_beam/io/gcp/bigquery_file_loads.py	86.60% <0.00%> (-4.51%)	⬇️
...hon/apache_beam/runners/direct/test_stream_impl.py	91.91% <0.00%> (-2.21%)	⬇️
...apache_beam/runners/dataflow/internal/apiclient.py	73.80% <0.00%> (-0.66%)	⬇️
...s/sdks/python/apache_beam/io/gcp/bigquery_tools.py	87.93% <0.00%> (-0.17%)	⬇️
...sdks/python/apache_beam/transforms/environments.py	87.85% <0.00%> (-0.08%)	⬇️
...ld/srcs/sdks/python/apache_beam/io/gcp/bigquery.py	75.52% <0.00%> (ø)
...uild/srcs/sdks/python/apache_beam/io/gcp/pubsub.py	92.15% <0.00%> (+0.03%)	⬆️
...ache_beam/runners/interactive/recording_manager.py	98.96% <0.00%> (+0.03%)	⬆️
...38/build/srcs/sdks/python/apache_beam/io/iobase.py	84.98% <0.00%> (+0.17%)	⬆️
...he_beam/runners/interactive/pipeline_instrument.py	99.47% <0.00%> (+0.26%)	⬆️
... and 7 more

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[chunyang]

Thanks, no worries! Busy end of quarter so I haven't had a lot of time to look at this.

[chunyang]

Hmm, I can't figure out why that doc error is happening. nvm, figured it out.

[pabloem]

Run Python 3.8 PostCommit

[pabloem]

Run Python 3.8 PostCommit

[pabloem]

LGTM thanks @chunyang !