feat: support reconnecting players to cluster

[jeremylvln]

Using the new transfer packets, we can now finish properly the proxy drain feature by reconnecting the players automatically when the TTL is expired.

Also, expose the method in the API if custom plugins want to re-use this capability.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (493ba07) 31.11% compared to head (d9b2141) 31.22%.
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #364      +/-   ##
==========================================
+ Coverage   31.11%   31.22%   +0.10%     
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  Files          58       58              
  Lines        3137     3142       +5     
==========================================
+ Hits          976      981       +5     
  Misses       2161     2161              

Flag	Coverage Δ
shulker-operator	58.42% <100.00%> (+0.14%)	⬆️

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Files	Coverage Δ
...lker-operator/src/reconcilers/proxy_fleet/fleet.rs	80.09% <100.00%> (+0.46%)	⬆️

[TehNeon]

One thing that would be nice is to have some sort of way to override the IP/Hostname it will transfer the users to. In my planned usage case I intend to be running on bare metal and utilizing an external DDoS protection provider (i.e TCPShield) which would require me to re-route the players to a specific hostname.

[jeremylvln]

One thing that would be nice is to have some sort of way to override the IP/Hostname it will transfer the users to. In my planned usage case I intend to be running on bare metal and utilizing an external DDoS protection provider (i.e TCPShield) which would require me to re-route the players to a specific hostname.

This would be a nice addition, indeed!