bitbake: bitbake: event: adding generic event for metadata usage

Adding the generic bb.event.MetadataEvent that is
targeted specifically at metadata usage. This is
needed in order to let the metadata code send and receive
events during asynchrous execution without having
to define each event specifically in Bitbake.

Metadata code should subscribe to and fire the MetadataEvent
in order to communicate asynchronously, and identify
the object using event.type field, and parse the
data in the event.data field.

Knotty UI will ignore these event by default.

This deprecates RequestPackageInfo/PackageInfo, and that
event pair will be removed in the future.

(Bitbake rev: ae1ea51aaab73e010d1c3db39df058bebebc11dd)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/knotty.py

@@ -477,6 +477,7 @@ def main(server, eventHandler, params, tf = TerminalFilter):
 
             # ignore
             if isinstance(event, (bb.event.BuildBase,
+                                  bb.event.MetadataEvent,
                                   bb.event.StampUpdate,
                                   bb.event.ConfigParsed,
                                   bb.event.RecipeParsed,