Convert TranslatedFont.prototype.loadType3Data to an asynchronous method

[Snuffleupagus]

The Type3 glyphs are parsed in series, which was implemented by chaining the getOperatorList promises together one after another.
Thanks to modern JavaScript this can be simplified a little bit, since we can just await within the loop instead.

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Smaller diff with https://github.com/mozilla/pdf.js/pull/21719/changes?w=1

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.05%. Comparing base (5f181fd) to head (74fe316).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21719      +/-   ##
==========================================
+ Coverage   90.03%   90.05%   +0.01%     
==========================================
  Files         264      264              
  Lines       66939    66936       -3     
==========================================
+ Hits        60267    60277      +10     
+ Misses       6672     6659      -13     

Flag	Coverage Δ
browsertest	66.47% <100.00%> (-0.03%)	⬇️
fonttest	9.03% <ø> (ø)
integrationtest	69.36% <0.00%> (+0.01%)	⬆️
unittest	57.97% <85.18%> (+<0.01%)	⬆️
unittestcli	56.71% <85.18%> (+0.02%)	⬆️

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[Snuffleupagus]

/botio browsertest

[moz-tools-bot]

From: Bot.io (Linux m4)

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Received

Command cmd_browsertest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.241.84.105:8877/cc8a32dd943d392/output.txt

[moz-tools-bot]

From: Bot.io (Windows)

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Received

Command cmd_browsertest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.193.163.58:8877/7c809e3caa4db3d/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/cc8a32dd943d392/output.txt

Total script time: 16.65 mins

• Regression tests: Passed

[moz-tools-bot]

From: Bot.io (Windows)

---

Success

Full output at http://54.193.163.58:8877/7c809e3caa4db3d/output.txt

Total script time: 23.41 mins

• Regression tests: Passed

[timvandermeij]

Thank you for simplifying this a bit!