add simplified scan option.

[MajdT51]

• use CompletableFuture from Paperlib to get the chunks async

• rename ScanRegionTask to ScanRegionTaskAdvanced

• introduce another calculate resources "strategy"

  • simplified
    • it checks if the ore has an air block near it. this means the the ore has high chance to be visible for players.
  • advanced:
  • the original implementation. It tries to find if there is a path (air, doors) to the ore

• the scan strategy is controlled by a new config called PopulationDensity.AdvancedScanStrategy of type boolean, which is set to true by default

• simplified vs advanced:

  • simplified: quick but delivers slightly higher resource numbers. It also limit the number of the counted coal and redstone ores
  • advanced: very slow and return lower resource number.

• scanregion command: /scanregion

  • checks the AdvancedScanStrategy config and run the related calculate resource strategy
  • use async loading of chunks for (simplified and advanced)
  • add a hint log to the calculate resource strategy

• the original implementation with sync chunk loading and advanced scan can be explicitly used with /scanregionoriginal.