feat: refactor peer selection for synchronization

[Freyskeyd]

Description

Switch from gatekeeper random peer to p2p layer random peer.
Basically dropping the support and management of the peers in the gatekeeper to only rely on the the network layer.

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

[codecov]

Codecov Report

Attention: 7 lines in your changes are missing coverage. Please review.

Comparison is base (014ddf6) 62.79% compared to head (2f445c7) 62.84%.
Report is 3 commits behind head on main.

Files	Patch %	Lines
...-tce-synchronizer/src/checkpoints_collector/mod.rs	50.00%	3 Missing ⚠️
crates/topos-tce/src/lib.rs	0.00%	2 Missing ⚠️
crates/topos-p2p/src/command.rs	0.00%	1 Missing ⚠️
crates/topos-p2p/src/runtime/handle_command.rs	95.23%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #382      +/-   ##
==========================================
+ Coverage   62.79%   62.84%   +0.04%     
==========================================
  Files         219      220       +1     
  Lines       11812    11760      -52     
==========================================
- Hits         7417     7390      -27     
+ Misses       4395     4370      -25     

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