Migrate endianconv unit tests to new test framework

[karthyuom]

This PR migrates all tests related to endianconv into new test framework as part of the parent issue https://github.com/valkey-io/valkey/issues/428.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 69.83%. Comparing base (cde8ec1) to head (98ba4e6). Report is 19 commits behind head on unstable.

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable     #458      +/-   ##
============================================
+ Coverage     68.91%   69.83%   +0.92%     
============================================
  Files           109      109              
  Lines         61793    61801       +8     
============================================
+ Hits          42582    43159     +577     
+ Misses        19211    18642     -569     

Files	Coverage Δ
src/endianconv.c	47.22% <ø> (ø)
src/server.c	88.60% <ø> (ø)

... and 36 files with indirect coverage changes

[karthyuom]

I didn’t remove the legacy endianconvTest from serverTest (see commit https://github.com/valkey-io/valkey/pull/458/commits/1c59ca7036977e06ad80de71cc501ea968071dc9 ) since it gives conflict which I couldn’t resolve anyway. I thought of doing it in a subsequent PR. I am not sure whethere there is any other alternative.

[karthyuom]

@madolson could you please review and merge the above, thanks.