Review: Memory allocation conventions #2
Description
Slab allocator is not needed for the string interning. It can have its own dedicated varena.
A UI_State's contextual stacks (layout/style/parent) can be allocated on the fly within the frame's varena as needed. There is no need to have them be fixed sized. (This maybe matters when there are multiple workspaces (Multiple UI_State contextes tabbed or tiled)