Removes filler accounts

[brooksprumo]

Problem

Filler accounts were used to stress the accounts db subsystem, but the pop-net clusters now are used instead.

Summary of Changes

Since the filler accounts are basically a hack, and no longer required, remove them.

[codecov]

Codecov Report

Merging #34115 (425e874) into master (32993b2) will increase coverage by 0.1%.
Report is 1355 commits behind head on master.
The diff coverage is 90.9%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #34115      +/-   ##
==========================================
+ Coverage    81.8%    81.9%    +0.1%     
==========================================
  Files         766      817      +51     
  Lines      209077   219725   +10648     
==========================================
+ Hits       171130   180125    +8995     
- Misses      37947    39600    +1653     

[jeffwashington]

lgtm. I imagine it is ok to just delete cli args and not deprecate. I seriously doubt ANYONE was using these.