Fix extractGeckoLogs for structured Log marker format (bug 2022540)

[padenot]

Bug 2022540 switched Log markers from {module, name} fields to structured {level, message} fields, with the module name stored as the marker name. The old format used a single module string that could include the log level prefix (e.g. D/cubeb); the new format uses an integer level field.

Profiles use one format exclusively, never a mix. We detect which by checking the first Log marker found in each thread. This also types things a little more.

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.44%. Comparing base (46e3594) to head (53f66c9).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/utils/window-console.ts	87.50%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5927      +/-   ##
==========================================
- Coverage   85.45%   85.44%   -0.01%     
==========================================
  Files         321      321              
  Lines       32068    32070       +2     
  Branches     8745     8744       -1     
==========================================
  Hits        27403    27403              
- Misses       4234     4236       +2     
  Partials      431      431              

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[canova]

Thanks!