NOTIF-315 Adds support for default behavior

[josejulio]

This PR adds a behavior group type that is not bound to an specifyc account_id. Instead it can be used globally across all accounts.

Default behavior group

The only considerated endpoint type for this kind of behavior groups is the EmailSubscription, and it needs to be global as well (account_id should be null).
There are new endpoints in the Internal API for managing this configuration:

• POST /defaultBehaviorGroups (BehaviorGroup)
  • Creates a default behavior group
• PUT /defaultBehaviorGroups/{behaviorGroupId}/actions (List of EmailSubscriptionProperties)
  • Updates the set of action of a default behavior group
• PUT /defaultBehaviorGroups/{behaviorGroupId}/eventType/{eventTypeId}
  • Links a default behavior group to an event type
• DELETE /defaultBehaviorGroups/{behaviorGroupId}/eventType/{eventTypeId}
  • Unlinks a default behavior group from an event type

Some remarks:

• A new response-only attribute is dynamically set to the behavior group: default_behavior. It is true when the account_id is null, false otherwise.
• This code also includes an utility (CommonStateSession) to easen the code when dealing with functions that could be used in both stateful and stateless. This could be potentially extracted as a separate PR to ease the review.

CommonStateSession

We use stateful sessions when dealing with REST calls and stateless sessions with kakfa events. There are some functions that we need in both places, instead of duplicating the function to run in both scenarios, a wrapper was created for a subset of operations.

The CommonStateSessionFactory provides a method to request a session depending our needs - The developer has to specify the state type, it doesn't autodetect anything.

Stateless sessions using this tool will attempt to mimic what one could expect with the stateful sessions. Currently it does use introspection to find if there is any method annotated with @PrePersit that should be called. This process is cached per class to avoid recomputing this on every call.

[gwenneg]

I only had a look at the sessions changes, this looks interesting!

[gwenneg]

FYI I will review the code again later, after most of the following comments have been resolved.

[gwenneg]

Sorry for the delay before I reviewed this BTW 😃

[josejulio]

@gwenneg I addressed most of the suggested changes

[josejulio]

Updated again!

[gwenneg]

I'm done reviewing the runtime code. I'll have a look at the test tomorrow.

[gwenneg]

LGTM

[gwenneg]

The PR check failures seem unrelated.