Structurify

• Added structure overlap prevention
• Added global and per namespace flatness checks, which means flatness check can now be configured globally, per namespace or per structure
• Added global and per namespace biome checks
• Added global and per namespace max/min distance from world center checks
• Added "step" as a configurable field for structures
• Added "terrain adaptation" as a configurable field for structures
• Added "size" as a configurable field for jigsaw structures
• Added "max distance from center" as a configurable field for jigsaw structures
• Added missing frequency description
• Improved flatness and biome check performance, now it should be actually unrecognizable opposite to the previous versions
• Improved overall runtime (world generation) performance of the mod by caching values
• Improved GUI workflows, setting up everything should be easier and more clear
• Fixed GUI, which can now be opened and reloaded from the game (in the world)
• Updated biome dropdown, which should now display the full id of biome/tag, so seemingly duplicate tags like "#minecraf:is_ocean" and "#c:is_ocean" can be recognized more easily
• Lot of other small tweaks/fixes

Be aware that there are so many changes that everything can be unstable/non working, so it felt right to mark this as an alpha first and wait for your feedback.