<set_var_types> wrapper that accepts tidyselect syntax.
Character vector-based selection still works.
set_var_types_x accepts xpose_data or xp_xtras objects.
set_var_types without _x is defined with S3 methods. To maintain xpose expectations,
the default method is <set_var_types>, but if an xp_xtras object
is used, the method uses set_var_types_x.