Update icon-for-X functions to take overrides
Update icon-for-X functions to take overrides

This allows you to call the functions with the same interface as the
insert icon functions, i.e. with params like `:height' and `:v-adjust'.

This means that you don't have to use the properties defined in the icon
alists if you don't want to.

domtronn/all-the-icons.el,domtronn/all-the-icons.el,domtronn/all-the-icons.el,domtronn/all-the-icons.el,domtronn/all-the-icons.el