Enhanced light bridge functionality: Use button type widget to allow protruding light bridges

[Critfish]

Description of the feature

As seen in Konclan's UCP, the protruding light bridge is a standard light bridge mounted on a 32x row of blocks, allowing it to point straight up or straight down, without needing to mount it on a floor or ceiling.

Instead of adding this as a separate item like the UCP does, this could be added to the default light bridge through the use of the Button Type dropdown widget, with weighted being the standard light bridge, cube being a protruding light bridge facing upwards, and sphere being a protruding light bridge facing downwards.

Light bridges take up no embed space, already use the 8-way handle, and don't already use the Button Type widget for anything else, allowing for this to be implemented seamlessly.

Why should this be implemented

This would improve the functionality and versatility of the light bridge element, allowing it to be positioned in configurations that weren't possible before, all without requiring an extra palette slot.

Additional information

[vrad-exe]

We can't use Button Type, only Cube Type and the various checkboxes

[Areng14]

Why not make it so that you can place it on the partial blocks

[FrozenDragon0]

Why not make it so that you can place it on the partial blocks

Don't think that's possible given that partial blocks are considered as items.

[HeimlichLaboratories]

I think you can only place test elements on walls, ceilings, and floors, and the partial blocks are considered items

[jb0lt]

Isn't there an 'item mounting' system in works or something

[vrad-exe]

There are vague plans for an item mounting system, but these particular combinations would be tricky to handle using that (how do you set which side of the block you want the bridge on?) so I think specifically implementing it as part of the light bridge item makes sense. Old BEE2 also had a sideways light bridge item (#95).

[vrad-exe]

Hmm, there are a couple problems with making this a part of the base light bridge though. First of all we can't move or hide the beam preview in the editor, so it'd still extend forward even if the bridge is pointed to the sides. Also, the regular light bridge uses a 6 position handle, but this needs to be 8 position so the blocks align properly.