[improve][broker][PIP-379] Don't replace a consumer when there's a collision

[lhotari]

Fixes #23439

Motivation

When a consumer joins or leaves, the hash ranges from existing consumers shouldn't move from one to another.

Modifications

• Revisit adding the to hash ring so that existing consumers aren't replaced when there are collisions.
• Add a test case which ensures this

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[equanz]

LGTM

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 56.25000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 74.23%. Comparing base (bbc6224) to head (cc54bf8).
Report is 667 commits behind head on master.

Files with missing lines	Patch %	Lines
...ce/ConsistentHashingStickyKeyConsumerSelector.java	53.33%	5 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #23441      +/-   ##
============================================
+ Coverage     73.57%   74.23%   +0.66%     
- Complexity    32624    34431    +1807     
============================================
  Files          1877     1953      +76     
  Lines        139502   147189    +7687     
  Branches      15299    16206     +907     
============================================
+ Hits         102638   109272    +6634     
- Misses        28908    29472     +564     
- Partials       7956     8445     +489     

Flag	Coverage Δ
inttests	27.65% <56.25%> (+3.07%)	⬆️
systests	24.35% <37.50%> (+0.03%)	⬆️
unittests	73.60% <56.25%> (+0.75%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...roker/service/ConsumerHashAssignmentsSnapshot.java	83.00% <100.00%> (ø)
...ce/ConsistentHashingStickyKeyConsumerSelector.java	92.15% <53.33%> (-2.08%)	⬇️

... and 636 files with indirect coverage changes