efl_access: Add reading_info_type set/get APIs
Information obtained by atspi client is name, role, description, state of an object.
reading_info_type_set/get APIs give control to application to decide on the information
that can be exposed.
The reading info is added as an attribute of an accessible object, on query of
attribute, reading_info_type and corresponding character buffer should be given to ATSPI clients.
Subscribers: cedric, govi, rajeshps, jpeg
Differential Revision: https://phab.enlightenment.org/D5524