efl_mono: Add support for Eina.Error/Empty in eina.Value
Summary:
eina.Value.Empty now means that we have an zeroed (empty) eina value.
For optional values that are empty use eina.Value.OptionalEmpty.
This was required to support the empty values passed with
EINA_VALUE_EMPTY in some Ecore futures.
Also, returning an eina_value by value is not supported in eolian
for safety reasons, so we removed some tests that tried to use this
behavior.
Depends on D6171
Reviewers: felipealmeida
Reviewed By: felipealmeida
Subscribers: cedric, zmike
Tags: #efl
Differential Revision: https://phab.enlightenment.org/D6172