MediaSDK has support for a number of rate control algorithms.
Adding all possible options to the property rate-control.

Fixme1: In case of failure, currently we don't have a proper method
to show which rate-control has been failed. It could be better
to add some extensive validation on EncQuery output in case of error.
Unfortunately, not all ratecontrol methods are supported by every codecs
and we don't have the dynamic detection of supported ratecontrol methods yet.

https://bugzilla.gnome.org/show_bug.cgi?id=791637