Load 'context' for local builds

'context' needed to be stored into the in-memory database and then
propagated for builds added to a MockModuleBuild with --add-local-build.

module_build_service/models.py

@@ -410,12 +410,14 @@ class ModuleBuild(MBSBase):
 
     @classmethod
     def create(cls, session, conf, name, stream, version, modulemd, scmurl, username,
+               context=None,
                copr_owner=None, copr_project=None, rebuild_strategy=None, publish_msg=True):
         now = datetime.utcnow()
         module = cls(
             name=name,
             stream=stream,
             version=version,
+            context=context,
             state="init",
             modulemd=modulemd,
             scmurl=scmurl,

module_build_service/resolver/PDCResolver.py

@@ -317,6 +317,7 @@ class PDCResolver(GenericResolver):
                     'ref': None,
                     'stream': local_build.stream,
                     'version': local_build.version,
+                    'context': local_build.context,
                     # No need to set filtered_rpms for local builds, because MBS
                     # filters the RPMs automatically when the module build is
                     # done.

module_build_service/utils/submit.py

@@ -535,6 +535,7 @@ def load_local_builds(local_build_nsvs, session=None):
             name=mmd.get_name(),
             stream=mmd.get_stream(),
             version=str(mmd.get_version()),
+            context=mmd.get_context(),
             modulemd=mmd.dumps(),
             scmurl="",
             username="mbs",