Implement launching 'metadata' and 'category' plugin

Implement launching 'metadata' and 'category' plugin

Implementation of loading other types of plugins of
pkgmgr than 'tag':
 - DynamicLibHandle was reworked to be base class of all plugins types,
 - add factory for plugin and common interface for them.

Following changes should be submitted together:
 - https://review.tizen.org/gerrit/#/c/59029/
 - https://review.tizen.org/gerrit/#/c/59028/
 - https://review.tizen.org/gerrit/#/c/59030/
 - https://review.tizen.org/gerrit/#/c/59031/

Change-Id: I7f6bd50e364bedac2ee18626db0b02cda4865e31