qga/qapi-schema: Refill doc comments to conform to conventions

qga/qapi-schema: Refill doc comments to conform to conventions

Sweep the entire documentation again.  Last done in commit
7270819384c (qga/qapi-schema: Refill doc comments to conform to
current conventions).

To check the generated documentation does not change, I compared the
generated HTML before and after this commit with "wdiff -3".  Finds no
differences.  Comparing with diff is not useful, as the reflown
paragraphs are visible there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20251103082354.3273027-5-armbru@redhat.com>