Fix swap of the main tile addon if a top object already exists in that tile

[Districh-ru]

The objects order on the same tile is determined by the current main addon object type (checked by getObjectTypeByIcn() function) and the layer type of the new tile being placed.

This PR fixes the getObjectTypeByIcn() function that was giving object type only for the main tile and giving OBJ_NONE for all other tiles. Now the function checks all object tiles.

It also forbids main addon swap if a new tile is the background layer one and the current tile already has an object with ID.

Master build:

fheroes2.2024-07-07.21-48-34-430.mp4

This PR:

fheroes2.2024-07-07.21-49-19-194.mp4

[ihhub]

Hi @Districh-ru , I left one comment here. Could you please take a look when you have time?

[github-actions]

⚠️ Clang-Tidy found issue(s) with the introduced code (1/1)

[Branikolog]

Hi!
If I place an artifact on a tile behind the castle - it still shown as artifact on right click on it:

After I pick it up the tile is shown as grass:

When the same cell without pre placed artifact belongs to castle area:

[Districh-ru]

Hi, @Branikolog, this bug also happens for the maps made by the original editor and we should fix it, but in a new PR IMHO. Because it is not Editor and new map format related but game engine related. :)

[ihhub]

Hi @Branikolog , this is the same issue as #8505 as it is not related to this PR.

[Branikolog]

Okay. No more issues found then. :)

[ihhub]

@Districh-ru , thank you so much for this fix!