Align rejected unblocked commands to update the correct error statistic

[ranshid]

Currently, in case a blocked command is unblocked externally (eg. due to the relevant slot being migrated or the CLIENT UNBLOCK command was issued, the command statistics will always update the failed_calls error statistic. This leads to missalignment with https://github.com/valkey-io/valkey/commit/90b9f08e5d1657e7bfffe43f31f6663bf469ee75 as well as some inconsistencies. For example when a key is migrated during cluster slot migration, clients blocked on XREADGROUP will be unblocked and update the rejected_calls stat, while clients blocked on BLPOP will get unblocked updating the failed_calls stat.

In this PR we add explicit indication in updateStatsOnUnblock thet indicates if the command was rejected or failed.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 70.78%. Comparing base (1acf7f7) to head (cd859c4). Report is 41 commits behind head on unstable.

Files with missing lines	Patch %	Lines
src/blocked.c	63.63%	4 Missing :warning:
src/module.c	0.00%	3 Missing :warning:

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable     #577      +/-   ##
============================================
+ Coverage     70.71%   70.78%   +0.07%     
============================================
  Files           119      119              
  Lines         64652    64699      +47     
============================================
+ Hits          45717    45800      +83     
+ Misses        18935    18899      -36     

Files with missing lines	Coverage Δ
src/server.h	100.00% <ø> (ø)
src/module.c	9.61% <0.00%> (-0.03%)	:arrow_down:
src/blocked.c	91.11% <63.63%> (-0.78%)	:arrow_down:

... and 51 files with indirect coverage changes

[madolson]

@ranshid Can you update this? I remember discussing this but I guess it fell between the cracks.

[hpatro]

Can you update this? I remember discussing this but I guess it fell between the cracks.

I don't have the context. @ranshid What's remaining here?

[ranshid]

@madolson @hpatro so sorry I missed that one. It is something I already did in Redis OSS and wanted to port it here. rebased and applied @hpatro suggestion.

[hpatro]

This is a minor change in behavior. @madolson Do you folks vote on this as well?