Rename "felix shell" command to "osgi framework command" so all low-level OSGi commands share the same command name prefix

Currently most low-level OSGi-related command names in Roo start with "osgi". The exception is "felix shell", which delegates a command directly to Felix infrastructure. The "felix" command name prefix adds an additional entry to the top-level command namespace and also couples us to Felix. It is preferable the command be renamed to "osgi framework command" for this reason.

Note: it is not expected normal Roo users would use the "osgi" commands. The "addon" commands are intended for normal day-to-day use by Roo users wishing to search, install and remove add-ons. The "osgi" commands are for troubleshooting, advanced users, add-on developers and alike.