Qmk_firmware: Cleanup: Remove extraneous includes from non-user keymaps

[skullydazed]

A lot of default keymaps have extraneous includes, some examples include:

#include "config_common.h"

#include "../../config.h`

To promote clean code we should remove these lines from all default keymaps and any keymap that is not owned by a user.

While changing these files we can also replace these old-style include guards with #pragma once:

#ifndef CONFIG_USER_H
#define CONFIG_USER_H
[...] /* rest of config.h here */
#endif

[drashna]

I decided to go through, and do this. As well as clean up the includes in the default keymap.c, as well as the _______ and XXXXXX defines.