Summary:
Uses a common helper to open and close namespaces, to get the managed
and unmanaged name of things, the interface, concrete and inherit class
names, etc.
eolian_cxx: Add namespace information to func_def, as it'll avoid
eolian-cxx clients dealing with the eolian C api directly when trying
to access a function pointer namespace.
Depends on D6048
Reviewers: felipealmeida, vitor.sousa
Reviewed By: vitor.sousa
Subscribers: cedric
Tags: #efl
Differential Revision: https://phab.enlightenment.org/D6049