TINKERPOP-3260: Browser testing for gremlin-javascript

[Iryna-Kahamlyk]

JIRA: https://issues.apache.org/jira/browse/TINKERPOP-3260

Summary

Adds two-tier smoke testing:

• Tier 1: Bundles the package and verifies that it loads successfully in headless Chromium, catching Node-only imports at build time.
• Tier 2: Verifies that browser transport can successfully round-trip HTTP requests to a real Gremlin Server.

Also includes unit tests for the new deepEqual function and browser authentication, along with a new CI job that runs both smoke test tiers.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.69%. Comparing base (a28cd1f) to head (77843b7).
⚠️ Report is 650 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3674      +/-   ##
============================================
+ Coverage     76.35%   76.69%   +0.33%     
- Complexity    13424    14336     +912     
============================================
  Files          1012     1037      +25     
  Lines         60341    64761    +4420     
  Branches       7075     7695     +620     
============================================
+ Hits          46076    49671    +3595     
- Misses        11548    11998     +450     
- Partials       2717     3092     +375     

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