Complete Feature of Online Servers List (Server+Client+Manager) & Compatibility Fix for NitroxServer on Linux

[DKingAlpha]

1. Compatibility for NitroxServer on Linux

This fixed the bug of nitroxserver on linux that used hardcoded backslash in path \\
It would fail to load cells on linux.

fix proof:
https://imgur.com/a/QTvA4DE

a wiki page of NitroxServer Setup on Linux will be added by shalix later.

2. Complete feature of Online Servers Menu

Server List is fetched from http://nitrox.qaq.link/server.
Server owner can choose to broadcast their server to http://nitrox.qaq.link/server
A Nitrox Server Manager is listening at nitrox.qaq.link to handle pings and serve lists

3. Fixed a spot of Log spam in EntityManager.cs

64c974b

[Sunrunner37]

Can you also weigh in on this PR: #574 Specifically the running in the background piece?

[DKingAlpha]

I have been in touch with Dilicor about that topic.

I would prefer using screen rather than nohup, screen worries about no background compatibility, but I will help that part.

[deejcoder]

I think we should try something along the lines of pm2, or supervisor, as these run applications in the background rather than foreground.

[DKingAlpha]

Hi, ServerInfo looks better now.

[DKingAlpha]

1. Catch Server Exit Event, gracefully exit.
2. NitroxServer will be able to broadcast its open information to a central server manager. This feature serves for OnlineServerList feature in NitroxClient.

Server Manager is under developing. Will finish in today.

My code always tries to keep compatibility with dual-stack IP. that made the code a bit more complex.

[DKingAlpha]

complete Online Server features finished.

Client side and Server side is in this PR

Server Manager code is at DKingCN/NitroxServerManager as simple as a single script

[Sunrunner37]

A few comments:

• Please break up PRs by using different GIT branches. That will limit the amount of churn on a PR and act as an isolated unit to review/merge.
• Ensure to action previous PR comments so we can merge.
• Removing the entity log line is just masking the problem. We should diagnose why this issue is occuring.
• As mentioned on discord, I already have a listing server in the works. Although I definitely appreciate the contribution.

[DKingAlpha]

1. The mess of PR is caused more like a historical reason. Feature didnt came as a whole part and Fixes are too small to split to another PR. Force push didnt made the PR cleaner, so I will close this one later and sort the update and create a new one.
2. I thought I finished the problem you mentioned in comments. Did I missed some?
3. You are right, masking the log is just making it worse.
4. I have done most of the feature before you could reply on discord, so I had to finish and share it as an option.