test(core): Adding coverage for key pre-releasing.

Added cases for the two use cases I know of:
    1. Rolling with key-repeat behavior
    2. Rolling symbols that have the same base key, eg `+=`

app/tests/modifiers/implicit/kp-rolling-symbols-same-key/events.patterns

@@ -0,0 +1,4 @@
+s/.*hid_listener_keycode_//p
+s/.*hid_register_mod/reg/p
+s/.*hid_unregister_mod/unreg/p
+s/.*zmk_hid_.*Modifiers set to /mods: Modifiers set to /p