feeds: use git-src-full to allow Git versioning

feeds: use git-src-full to allow Git versioning

Both $(AUTORELEASE) and $(PKG_SRC_VERSION) (from luci.git) use the Git
log to determine releases and package timestamps.

Feeds are shallow cloned by default, resulting in an incomplete Git log
and therefore different local package versions than offered upstream.

This commits sets the default feeds to use `src-git-full` to solve that.

Add fixes from "2b1d92f: scripts/feeds: silence git warning by selecting
pull style" to `src-git-full`

Signed-off-by: Paul Spooren <mail@aparcar.org>
(cherry picked from commit 7fae1e5677e9bb4979c8d4ac99be4de6955b13d0)