Fix use of shifted custom keycode (#18978)

Fix keycode parameter extraction to match the new DD keycodes (#18977)

* Add macros to extract parameters from keycode values

Implement both encoding and decoding for keycodes like TO(layer) or
LM(layer, mod) in one place, so that the decoding won't get out of sync
with the encoding.

While at it, fix some macros for creating keycode values that did not
apply the appropriate masks to parameters (and therefore could allow the
result to be out of range if a wrong parameter was passed).

* keymap_common: Use extraction macros for keycodes

* pointing_device_auto_mouse: Use extraction macros for keycodes

Fixes #18970.

* process_autocorrect: Use extraction macros for keycodes

* process_caps_word: Use extraction macros for keycodes

(Also fix a minor bug - SH_TG was not handled properly)

* process_leader: Use extraction macros for keycodes

(Technically the code is not 100% correct, because it always assumes
that the LT() or MT() action was a tap, but it's a separate issue that
already existed before the keycode changes.)

* process_unicode: Use extraction macros for keycodes

* process_unicodemap: Use extraction macros for keycodes

`handwired/swiftrax/walter`: fix layout mismatch (#18974)

* `handwired/swiftrax/walter`: fix layout mismatch

* Undo K4A removal, fix info.json instead

Merge remote-tracking branch 'origin/master' into develop

Reworked backlight keycodes. (#18961)

Co-authored-by: Ryan <fauxpark@gmail.com>

[Bug] Fix compilation issue with WPM (#18965)

[Keyboard] Add Work Louder Numpad (#18912)

* [Keyboard] Add Work Louder Numpad

* Add future proofing for rgb matrix

* Update readme

* fixup copyright headers

* Actually enable via

Align audio keycode names (#18962)

* Align audio keycode names

* Update docs

* Update quantum

Align dynamic tapping term keycode names (#18963)

* Align dynamic tapping term keycode names

* regen header

Remove thermal printer. (#18959)

Macro keycode name refactoring (#18958)

Reduce includes for send_string header (#18952)

Initial DD keycode migration (#18643)

* Initial DD keycode migration

* Sort magic keycodes

Remove hardcoded VIA keycode range (#18956)

Fix "no matrix definition" errors for some boards (#18954)

Formalise keyboard- and user-specific EEPROM blocks (#18874)

* Formalise keyboard and user eeconfig datablocks.

* Add debounce helper that checks a condition and issues post-write function invocation.

* Naming.

Reduce includes for dip_switch header (#18951)

Fix DD warnings for RGBKB boards (#18944)

Reduce includes for wpm header (#18949)

Reduce includes for caps_word header (#18948)