Core: Add settings API ("auto settings") for host.yaml (#1871)

* Add settings API ("auto settings") for host.yaml

* settings: no BOM when saving

* settings: fix saving / groups resetting themselves

* settings: fix AutoWorldRegister import

Co-authored-by: el-u <109771707+el-u@users.noreply.github.com>

* Lufia2: settings: clean up imports

* settings: more consistent class naming

* Docs: update world api for settings api refactor

* settings: fix access from World instance

* settings: update migration timeline

* Docs: Apply suggestions from code review

Co-authored-by: Zach Parks <zach@alliware.com>

* Settings: correctly resolve .exe in UserPath and LocalPath

---------

Co-authored-by: el-u <109771707+el-u@users.noreply.github.com>
Co-authored-by: Zach Parks <zach@alliware.com>

inno_setup.iss

@@ -182,6 +182,7 @@ Name: "{commondesktop}\{#MyAppName} Undertale Client"; Filename: "{app}\Archipel
 Filename: "{tmp}\vc_redist.x64.exe"; Parameters: "/passive /norestart"; Check: IsVCRedist64BitNeeded; StatusMsg: "Installing VC++ redistributable..."
 Filename: "{app}\ArchipelagoLttPAdjuster"; Parameters: "--update_sprites"; StatusMsg: "Updating Sprite Library..."; Components: client/sni/lttp or generator/lttp
 Filename: "{app}\ArchipelagoMinecraftClient.exe"; Parameters: "--install"; StatusMsg: "Installing Forge Server..."; Components: client/minecraft
+Filename: "{app}\ArchipelagoLauncher"; Parameters: "--update_settings"; StatusMsg: "Updating host.yaml..."; Flags: runasoriginaluser runhidden
 
 [UninstallDelete]
 Type: dirifempty; Name: "{app}"