Increase message and subscription buffer size to 128

[masih]

Increase the pubsub and internal message queue buffer sizes to 128. This is to allow a larger headroom for buffered messages if the internal message handling loop is too slow, or in a case where there is a slight missalignment across nodes on bootstrap.

Fixes #759

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 69.71%. Comparing base (c4d8f53) to head (e021971).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #762      +/-   ##
==========================================
- Coverage   69.81%   69.71%   -0.11%     
==========================================
  Files          74       74              
  Lines        7553     7557       +4     
==========================================
- Hits         5273     5268       -5     
- Misses       1869     1876       +7     
- Partials      411      413       +2     

Files with missing lines	Coverage Δ
host.go	66.02% <100.00%> (+0.65%)	⬆️

... and 3 files with indirect coverage changes