Added duduping on mb_trackid to the duplicates plugin

[tommyschnabel]

Description

plugins/duplicates: dedupe_mb_trackid_on_import option added to deduplicate during imports based on already-imported mb_trackid.

To Do

• Documentation. (If you've added a new command-line flag, for example, find the appropriate page under docs/ to describe it.)
• Changelog. (Add an entry to docs/changelog.rst to the bottom of one of the lists near the top of the document.)
• Tests. (Very much encouraged but not strictly required.)

[codecov]

Codecov Report

❌ Patch coverage is 20.83333% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.01%. Comparing base (3d3f5e3) to head (50152df).

Files with missing lines	Patch %	Lines
beetsplug/duplicates.py	20.83%	19 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6313      +/-   ##
==========================================
- Coverage   72.07%   72.01%   -0.07%     
==========================================
  Files         159      159              
  Lines       20633    20656      +23     
  Branches     3273     3279       +6     
==========================================
+ Hits        14871    14875       +4     
- Misses       5053     5072      +19     
  Partials      709      709              

Files with missing lines	Coverage Δ
beetsplug/tidal/__init__.py	85.32% <ø> (ø)
beetsplug/duplicates.py	19.68% <20.83%> (-0.32%)	⬇️

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.