gobject-introspection: split tools and giscanner into a separate package

gobject-introspection: split tools and giscanner into a separate package

The tools and giscanner require python3-setuptools at runtime. This increases
the image size quite a bit (on my end ~1.7MB compressed). Most users don't need
these tools in the final image so make them optional.

This commit introduces a new packcage gobject-introspection-tools

Signed-off-by: Guðni Már Gilbert <gudni.m.g@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>