Add standard namespace and metadata

[LeoColomb]

Using Bitnami common helpers from #184 to provide the following:

• Correctly namespaced entities
• Labels and annotations with proper merging function (to avoid duplications and errors)
• More validations around metadata (length of names is crucial, as much as other structure)

[RangerRick]

Lost of changes, but hey, we have tests now, and everything checks out. Ship it!