Disable trackball when typing

[bstiq]

Requested feature.

Add a #define in the configuration that disables the trakball / trackpad when typing.

As per Dasky's code:

static uint32_t last_keyboard_keypress = 0;
static bool     mouse_button_held      = false;
extern void     last_pointing_device_activity_trigger(void);

bool process_record_keymap(uint16_t keycode, keyrecord_t* record) {
    if (!IS_MOUSE_KEYCODE(keycode) && !IS_KB_KEYCODE(keycode)) {
        last_keyboard_keypress = timer_read32();
        layer_off(_POINTING);
    } else {
        mouse_button_held = record->event.pressed;
        last_pointing_device_activity_trigger();
    }
    return true;
}

void housekeeping_task_keymap(void) {
    if (!mouse_button_held && IS_LAYER_ON(_POINTING) && last_pointing_device_activity_elapsed() > 900) {
        layer_off(_POINTING);
    }
}

report_mouse_t pointing_device_task_user(report_mouse_t mouse_report) {
    if (timer_elapsed32(last_keyboard_keypress) < 100) {
        mouse_report.x = 0;
        mouse_report.y = 0;
    }
    if (abs(mouse_report.x) > 2 || abs(mouse_report.y) > 2) {
        if (get_highest_layer(layer_state) == _QWERTY) {
            layer_on(_POINTING);
        }
    }
    return mouse_report;
}