review template_feed cmfpackage.json files

[joaoopereira]

All template files should be reviewed:

1. Remove the following properties (and set them as default in the respective handler):

• isInstallable
• isUniqueInstall
• xmlInjection

[joaoopereira]

We should also review the contentToPack.
It make sense in some scenarios to remove from template, and make all the logic behind the scenes using defaults.

Keeping the backdoor to add more contentToPack