[packaging] first step towards subtrees

Signed-off-by: Simonas Leleiva <simonas.leleiva@jollamobile.com>
Squashed 'qtquickcontrols/' content from commit 6e42962

git-subtree-dir: qtquickcontrols
git-subtree-split: 6e42962551db34b9c6144040fb6c9de9029946a4
Merge commit 'faddc4ef53467c31e0d1a5df2537004a82238d31' as 'qtquickcontrols'