New Glass block: Window Panels

This is an amalgamation of other similar ideas.

Window panels are glass blocks that can be placed on the edge of a block, similar to doors and trapdoors and unlike glass panes. They are crafted from glass panes and an additional material: wood, iron, copper. This means there are wood, iron and copper window panels. The material determines the texture of window panels (for example, wooden window panels can have the wooden crossed beams (plus shape) texture on them). Window panels can be broken without Silk Touch.

It is possible to place multiple window panels per block (like it is the case with candles and chiseled bookshelves). This allows you to place up to 6 window panels per block.

All of this allows for the following uses in building:

- horizontal window panels for floors and ceilings

- placing a window panel on the edge of two blocks, allowing the inner wall and the outer wall to be separated with a window (which is not possible with glass panes since they are placed in the middle of a block)

- since they can be waterlogged, they allow for small, block-sized aquariums

- the textures can be made to suit different architectural styles: wood for medieval, iron for modern, etc.

Overall, it can just be a very cool block from a technical standpoint, since there is nothing like that in the game.