Ensures All doors in blueprint are saved as closed

[Doc-1]

This is to fix a certain issue when saving an already opened door into a blueprint. It does not reset the NBT tag "opened" to false. It remaining true prevents it from opening properly.

[CreativeMD]

There is a method in LittleStructureType called finalizePreview, rather do it there. I think you basically do the same thing in LittleDoorBaseType. Not sure if this is an issue in 1.20. Furthermore I still do not understand 100% why this actually causes any issues. Have not found the time yet to look into it.

[Doc-1]

This causes an issue with auto-opening doors. When you save an already opened, auto-opening door, and place it in the world. The door does not update it's signaling to auto-open the door.
How to reproduce:

1. Create a door with a signaling of 1=b0.
2. Place the door down.
3. Place a tile and save the door plus tile.
4. Place the new save down. The door will remain closed.

This is where the door's state not being reset to 0 causes the issue.

LittleTiles/src/main/java/com/creativemd/littletiles/common/structure/type/door/LittleDoor.java

Line 175 in 286a797

if (opened != output.getState()[0] && !isInMotion())

[CreativeMD]

But your fix would mean that the door state will get switched, in case you pick up the structure in the opened state and save it in the blueprint again.