Agricultural tower grappler current position read

[Osmo]

With the new agricultural tower features it opens up possibilities to use it for more than just agriculture. For my usecase i'd like to be able to draw with LuaRendering at the position of the crane, as an item icon won't be enough. It is currently possible to read the destination of the crane/grappler, but not their current position.
I'm asking for a LuaEntity::crane_grappler_position (and/or a 3d variant) to read the current position of the grappler.

[Lou]

added a read LuaEntity::crane_end_position_3d that returns current position of the crane end for 2.0.50