adapts unicode to quantum.c (#333)

adapts unicode to quantum.c (#333)

* Unicode

to have unicode input you need to:

- set your OS input method to UNICODE if needed
- enable unicode in your makefile
- copy the action_function from
keyboard/planck/keymaps/unicode/unicode.c to your keymap.c
set the target OS method in your keymap.c: void matrix_init_user() {
set_unicode_mode(UC_OSX); } you can then switch when you want with:
set_unicode_mode(UC_OSX); set_unicode_mode(UC_LNX);
set_unicode_mode(UC_WIN);
put some unicode codes in your keymap like so: UC(0x0061)
I did change the bit mask in quantum/keymap_common.c and .h
I’m afraid we will need uint32 to get a total support for all unicode
tables or relocate the handler as @mbarkhau did.

* rearranges keycode values, hooks-up unicode

* removes extra lalt ref

* adds unicode shortcuts and example