Update Ruby-templates to support generation of v4 UUIDs

[FangioD]

In utils.rb of the Ruby-template, def generate_uuid does not return a v4 UUID.
It could be replaced by the function uuid of the module SecureRandom.
This would ensure consistency over the different templates.

[FangioD]

Preferably, the UUID should be monotonic, so version 1 would probably also an option.