encode/unittest: add simple quality set/get test for jpeg
encode/unittest: add simple quality set/get test for jpeg

Simple unittest to verify set/get of jpeg quality parameter
behaves as expected.

Also, update simple encode test to verify quality level
persistence throughout encode process.

Signed-off-by: U. Artie Eoff <32aece0d55055227b44d04b7d0051cf3d04ee871@intel.com>

YuJiankang/libyami,YuJiankang/libyami,01org/libyami,01org/libyami,01org/libyami,YuJiankang/libyami