feat: remove the register commands macro

[gruberb]

Description

Remove not needed RegisterCommands macro, which was used for GetAllSubnets in the Gatekeeper client. This is not needed anymore.

Fixes TP-562

PR Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (6e72999) 65.71% compared to head (8c4de78) 67.37%.
Report is 5 commits behind head on main.

Files	Patch %	Lines
crates/topos-tce/src/lib.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #426      +/-   ##
==========================================
+ Coverage   65.71%   67.37%   +1.65%     
==========================================
  Files         223      219       -4     
  Lines       11921    11882      -39     
==========================================
+ Hits         7834     8005     +171     
+ Misses       4087     3877     -210     

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[gruberb]

Seems like we don't use GetAllSubnets anymore. Or am I wrong @Freyskeyd?

[Freyskeyd]

The gatekeeper is useless for now as we do not handle the validators in it. We'll need to re-add some part when working on it later.