Fix one vs one-apps versioning

[xorel]

Sync again the OpenNebula and one-apps(context packages) versions

Description In share/context/download_context.sh we previously had a logic which pick the same one-context packages version as the OpenNebula.

With introducing the one-apps we broke this, as

• we released 6.10 one-apps before OpenNebula 6.10
• we don't have 6.4 one-apps release

In 6.9.80 we included latest one-apps release but some better logic should be implemented, such as following:

Install latest context pacakges of the same major version as OpenNebula

e.g. in 6.10.X OpenNebula we will always add latest 6.10 one-apps