[BEAM-11045] Fix screendiff integration tests

[KevinGG]

1. Removed the server daemon process from screen diff tests because it's
   not compatible with Py3.8. Replaced it with a lightweight daemon thread.
2. Upgraded chromedriver-binary version to 85 to match the newest chrome
   browser version and updated the goldens to match the iframe changed
   introduced in PR#13045.

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Choose reviewer(s) and mention them in a comment (R: @username).
• Format the pull request title like [BEAM-XXX] Fixes bug in ApproximateQuantiles, where you replace BEAM-XXX with the appropriate JIRA issue, if applicable. This will automatically link the pull request to the issue.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

Post-Commit Tests Status (on master branch)

Lang	SDK	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	---		---	---	---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI.

[codecov]

Codecov Report

Merging #13052 into master will decrease coverage by 0.00%.
The diff coverage is 22.22%.

@@            Coverage Diff             @@
##           master   #13052      +/-   ##
==========================================
- Coverage   82.49%   82.48%   -0.01%     
==========================================
  Files         455      455              
  Lines       54867    54870       +3     
==========================================
- Hits        45263    45261       -2     
- Misses       9604     9609       +5     

Impacted Files	Coverage Δ
...ers/interactive/testing/integration/screen_diff.py	28.45% <0.00%> (+0.54%)	⬆️
...hon/apache_beam/runners/dataflow/internal/names.py	100.00% <100.00%> (ø)
sdks/python/apache_beam/utils/interactive_utils.py	92.85% <0.00%> (-2.39%)	⬇️
sdks/python/apache_beam/io/localfilesystem.py	91.66% <0.00%> (-0.76%)	⬇️
sdks/python/apache_beam/io/gcp/bigquery_tools.py	87.79% <0.00%> (-0.57%)	⬇️
...hon/apache_beam/runners/worker/bundle_processor.py	94.34% <0.00%> (-0.14%)	⬇️
...beam/runners/portability/local_job_service_main.py	0.00% <0.00%> (ø)
...runners/interactive/display/pcoll_visualization.py	85.34% <0.00%> (+0.07%)	⬆️
sdks/python/apache_beam/io/iobase.py	84.03% <0.00%> (+0.28%)	⬆️
...eam/runners/interactive/interactive_environment.py	89.80% <0.00%> (+0.35%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a27faca...8d19542. Read the comment docs.