9c98ea1a18
This converts `eButType` and `eButPointerType` as typed enums.
This improves a bit `uiDefBut` self-documentation by taking an
struct with `ButType` and `ButPointerType` types, instead of
using a single `int` to write both enum types and bit index.
Almost all other `uiDefBut*` functions take just a `ButType`
parameter now.
`uiDefButI` for example is equivalent to:
`uiDefBut({ButType(type), ButPointerType::Int},...);`
Pull Request: https://projects.blender.org/blender/blender/pulls/142132