lib/oelite: Improve local repo git fetching
lib/oelite: Improve local repo git fetching

* Add proper signature handling for local git branches, ensuring rebuild
  when necessary.
* Fix bug in handling of clean local branches.
* Handle local git detached head fetching.

Signed-off-by: Esben Haabendal <c5ba3f1141bb30a64dd6c7e6726a53a85adc9442@prevas.dk>

hundeboll/core,sknsean/core,hundeboll/core,hundeboll/core,sknsean/core,diorcety/oe-lite-core,sknsean/core,diorcety/oe-lite-core,sknsean/core,hundeboll/core,sknsean/core