Add Peaceful town public spawns

[Goosius1]

Description:

• Since SW2.0.0, on servers with public /n spawns but not public /t spawns .... peaceful towns cannot maintain a stable public spawn, because the only one posssible is /n, and they cannot defend it.
• This is a big problem for peaceful shopkeepers, who on those servers, often create "Shell Nations", using no other features except the nation spawn.
• Ideally those shopkeepers could use the kind of transport system without any political baggage, such as public /t spawns or some sort of new road feature, however the first is not always possible and the second doesn't seem to be available at present.
• This PR mitigates the issue by providing all Peaceful towns by default with a public spawn.
• This PR also increases the default peacefulness-switch time from 5->7 days, to help ensure that towns which aren't really peaceful don't see this as a reason for switching back and forth between peaceful/non-peaceful.

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New Nodes/Commands/ConfigOptions:

  # If this is true, peaceful towns have a public spawn.
  # 
  # TIP 1:
  # In Towny in 2023, many peaceful-builder players have a Critical Requirement to own public/effectively-public spawns, 
  # so that they can run-shops/demonstrate-builds.
  # In Servers configured for public /n spawns, but not public /t spawns, players often create 'Shell Nations', 
  # which they use just for the /n spawns.
  # SiegeWar cannot/will-not protect 'Shell Nations',
  # Thus, if your server is configured this way, set this value to 'true' to meet a critical requirement for peaceful-builder players.
  # 
  # TIP 2:
  # In Towny in 2023, the reason some servers disable public /t spawns, is to encourage 'infastructure' between towns.
  # While this is an interesting goal, it is is probably not as important as meeting the critical player requirement outlined above,
  # Thus although this feature could potentially interfere with infrastructure,
  # the problems it solves are probably more important than the problems it creates
  public_spawn_enabled: 'true'

---

Relevant Issue ticket:

Closes #831

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• I have tested this pull request for defects on a server.

By making this pull request, I represent that I have the right to waive copyright and related rights to my contribution, and agree that all copyright and related rights in my contributions are waived, and I acknowledge that the TownyAdvanced organization has the copyright to use and modify my contribution under the SiegeWar License for perpetuity.

[LlmDl]

One unneeded diff to clean up, otherwise good to go.

[LlmDl]

Unneeded diff in this class.