[backend] don't delete data too early in get_projpacks, update_projpacks is much saner

Also add new 'delayed startup' package error handling, just in case...
[api] handle removal of repositories which are defined as release targets in a correct way (fixes database corruption)
[backend] also add the hybrid attribute to the type

Kiwi reads some bits from type, other bits are read in KIWICollect ;(
[webui] More verbose search results for packages/projects