Gets rid of some unneeded property notification functions in GES

- enable is_equal function again (unsure why it was disabled)
- remove restriction-caps property, encoding-profile objects are
immutable
- remove cast need by using IsA<EncodingProfile> in parameters and
returning the correct type of encodingprofile subclass from the build()
functions. It used a internal hack for storing those IsA objects in
order to keep the API clean and ready to be used, this should be sorted
out as soon as we figure out how to store them in the buidlers.
- encodebin example: remove Result error propagation when it is caused
by programming mistakes. A panic will happen in those cases.
- run rustfmt

Avoid refcounting mistakes by using the right converting functions
before calling the ffi layer functions

Provide builders for the EncodingProfile so that the created objects are
imutable and can have the Send and Sync traits

Regenerate with latest gir to get rid of unneeded notify signal connectors for construct-only properties

Or silence the ones we don't care about.