Simon McVittie authored May 18, 2022 and Ralf Habacker committed May 27, 2022

Having the full text of the AFL-2.1 and GPL in this file makes it harder
to find the unique information, which is the summary. Move their full
text into LICENSES/ (consistent with how REUSE handles this), leaving
a short summary of the licensing situation in COPYING.

Loosely based on work from Ralf Habacker in dbus!304.

Signed-off-by: Simon McVittie <smcv@collabora.com>