this doesn't support editing the rear side of a sign, since the 1.12 format doesn't allow us to represent the rear text, and it would necessitate API breaks to support anyway.
However, we can quite trivially support APIs for the sign GUI, which plugins can use to enable editing signs. PocketMine-MP doesn't currently permit this, since it's currently an experimental feature in 1.20, but plugins can simply use Player->openSignEditor() to mimic it.
This is, however, a byproduct of the fact that APIs needed to be added in order to facilitate the use of OpenSignPacket in 1.19.80.
fixes#4856fixes#458fixes#4529fixes#3299
Added API method Block::getSupportType(Facing) : SupportType
Added SupportType enum
fixes torch, lantern, door etc. placement on slabs and upside-down stairs
This change was made after exploring turning this into a permission. It occurred to me that this feature is entirely superfluous because it's non-vanilla, can be done by plugins, and is usually considered as a bug. In addition, disabling this behaviour required third party code just for this one thing because it was not able to be managed by a permissions plugin.
Instead, it's better to produce a plugin which implements this behaviour if it's desired, by making use of SignChangeEvent and PlayerChatEvent/PlayerCommandPreprocessEvent.
close#3856, close#2288
