feat: SQLTap connector instance shared with streams

[BuzzCutNorman]

This adds a variable _tap_connector to SQLTap to house an instance of the default_stream_class.connector_class and a property to access it. The catalog_dict and discover_streams methods were updated to utilize the new property.

Closes #1773

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📚 Documentation preview 📚: https://meltano-sdk--1861.org.readthedocs.build/en/1861/

[codecov]

Codecov Report

Merging #1861 (ace7142) into main (efca24f) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1861      +/-   ##
==========================================
+ Coverage   86.95%   86.97%   +0.01%     
==========================================
  Files          59       59              
  Lines        5084     5090       +6     
  Branches      823      824       +1     
==========================================
+ Hits         4421     4427       +6     
  Misses        466      466              
  Partials      197      197              

Files Changed	Coverage Δ
singer_sdk/tap_base.py	83.84% <100.00%> (+0.43%)	⬆️

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[BuzzCutNorman]

Just wanted to check in on this PR. Thanks

[edgarrmondragon]

I'm gonna give this a try with MeltanoLabs/tap-postgres

[edgarrmondragon]

Thanks @BuzzCutNorman!