VStream API: Reset stopPos in catchup

[beingnoble03]

Description

When fastforward runs the stopPos for uvStreamer is set to the gtid of the snapshot taken by the next copy. However it never gets reset. Both catchup and fastforward use the same callback wrapper where, after processing a transaction, it checks against the stopPos

This causes catchup to prematurely exit with an EOF when there are multiple tables and there are updates or deletes for transactions to catch up on for tables/rows that are already copied during the copy phase.

Related Issue(s)

• Fixes VStream: Reset stopPos in catchup #18120

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Deployment Notes

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[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 1 line in your changes missing coverage. Please review.

Project coverage is 67.54%. Comparing base (8ee1f29) to head (5de595f).

Files with missing lines	Patch %	Lines
...o/vt/vttablet/tabletserver/vstreamer/uvstreamer.go	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #18119      +/-   ##
==========================================
- Coverage   67.56%   67.54%   -0.02%     
==========================================
  Files        1601     1601              
  Lines      261416   261424       +8     
==========================================
- Hits       176618   176586      -32     
- Misses      84798    84838      +40     

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