Add Gondolindrim's keymap for Evolv: addition of "encoder modes" (qmk…

…#14943)

* Update encoder callback

* Move encoder callback

- Encoder callback function was moved from ``encoder_update_user`` in ``keymap.c`` to ``encoder_update_kb`` in ``keyboard.c``

* Update keyboards/evolv/rules.mk

Co-authored-by: Ryan <[email protected]>

* Use tap_code() on encoder callback

Co-authored-by: Ryan <[email protected]>

* Use tap_code_delay

* Minor readability changes

Co-authored-by: Ryan <[email protected]>
Co-authored-by: Nick Brassel <[email protected]>