insane.bbclass: add do_recipe_qa task

insane.bbclass: add do_recipe_qa task

There is a need to run QA checks that can operate entirely from
recipe metadata and do not need any of the build artefacts or
source code. After some deliberation it was concluded that such
checks are best collected in their own task that runs as early as possible,
and so this commit adds the task.

Like package_qa, the task is sstate enabled, but doesn't (yet)
register the qa results into sstate.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>