feat: Add mDNS and Rendezvous configs

[bgins]

Description

This PR implements the following features:

• Add enable_mdns config
• Add enable_rendezvous config

These configs determine whether we toggle mDNS and Rendezvous on or off. In addition, we check the toggle states in event handlers where we might use mDNS or Rendezvous.

Link to issue

Closes #376

Type of change

• New feature (non-breaking change that adds functionality)
• Refactor (non-breaking change that updates existing functionality)

Test plan (required)

All existing tests should pass. In particular, we are interested in the multi-node tests that rely on known peers and mDNS.

[codecov]

Codecov Report

Merging #377 (b9d0e25) into main (b0bda83) will decrease coverage by 0.11%.
Report is 2 commits behind head on main.
The diff coverage is 29.31%.

@@            Coverage Diff             @@
##             main     #377      +/-   ##
==========================================
- Coverage   72.24%   72.14%   -0.11%     
==========================================
  Files          69       69              
  Lines        6872     6889      +17     
==========================================
+ Hits         4965     4970       +5     
- Misses       1907     1919      +12     

Files	Coverage Δ
homestar-runtime/src/settings.rs	98.22% <100.00%> (+0.02%)	⬆️
homestar-runtime/src/network/swarm.rs	58.22% <83.33%> (-0.33%)	⬇️
homestar-runtime/src/event_handler/swarm_event.rs	16.52% <0.00%> (-0.33%)	⬇️