[EDGEHOG-DEVICE-RUNTIME] Add new version 0.7.0
Add new version 0.7.0 and make it the default choice.
Due to the fact that the release 0.7.0 has different management of astarte_sdk, a new recipe has been added, instead of replacing the already existing one.
the bb files of the recipes now have the version in use specified as suffix. This change has been done because in the future more than one version of the software will be present. In this way, a default version can be defined (via PREFERRED_VERSION variable).
In conf/distro/include/edgehog-base.inc is present the following variable:
EDGEHOG_DEVICE_RUNTIME_VERSION
which defines the version to use (actually 0.7.0).