elm gengrid/genlist: Changed 'label_get' to 'text_get' according to the

elm gengrid/genlist: Changed 'label_get' to 'text_get' according to the
recent elementary api corrections.

I changed item class's 'label_get' to 'text_get'. But 'label_get' is still
supported by union structure. So 'label_get' will just give you
deprecated warnings while compiling but it's recommended to fix your
apps to 'text_get'. Sometimes when you initialize item class using
braces, you will get 'missing braces around initializer' but ignore
this. That warning will be gone after I remove 'label_get' backport. I
will remove this 'label_get' backport after I finish below
jobs.

[TODO]
1. Fix all apps in trunk.
2. Change edc "labels" to "texts" as well. I haven't done this yet.

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/elementary@65751 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33