[Shared infra] Add support for all address types

In the shared infra design doc, the ability to create 'transactional' queues and topics are indicated by an array of capabilities on the MessagingPlan:

kind: MessagingPlan
spec:
  capabilities:
  - transactional

In addition to enforcing this at the messaging plan, I wonder if it should be possible to specify this property on the MessagingTenant as well. This allows making use of transactional addresses without having to create a MessagingPlan. It could be exposed like this:

kind: MessagingTenant
spec:
  # For user setting the capability
  capabilities:
  - transactional
status:
  # The capabilities as inferred by the operator, either based on plan or on the setting in the spec.
  capabilities:
  - transactional

Question 1: Should it be possible to override the plan in the MessagingTenant ?

If a MessagingTenant has the transactional capability, the MessagingAddress controller can:

Use a 'transactional scheduler' to enforce all addresses for that tenant to be created on the same broker
Configure the linkRoute in the router for all addresses with prefix of the tenant namespace

I think the simplest way to implement this in the operator is to create this link route when the first address is created belonging to a tenant with transactional capability is created. Once that address has been scheduled, the operator can then know what parameters the linkRoute should have.

Question 2: Does this sufficiently cover the use cases of a JMS/Transactional broker? I.e. do we need to allow clients to use this virtual broker without any addresses configured?

@k-wall @rgodfrey Any concerns/comments to this?

EnMasseProject / enmasse

[Shared infra] Add support for all address types #4469