Those types needed the following code in apply:
if builtins.isString value
then mkRaw value
else value
This commit avoids this boilerplate, and clarifies that the `str` is lua
code in the documentation.
This allows to avoid calling `mkRaw` on lua functions, as they will get
applied automatically.
This could also help in the future to refactor the use of Lua code to
make it more user-friendly.