Add Behavior support to RDE Interfaces and RDE Types

[adambarreiro]

Overview

This PR complements #965, #973 and #977 as it adds support to create, read, update and delete Behaviors, both in RDE Interfaces and Types.

This PR requires vmware/go-vcloud-director#584.

Context

Behaviors are explained here, but in simplified words, they're "procedures" that belong to RDE Interfaces, are inherited by the RDE Types that use those Interfaces and are invoked on the RDEs that instantiate those types.

Also, Behaviors can be overridden at the RDE Type level. For example, if you use a RDE Interface with behavior "A", you can override what it does in a Type that uses it.

Last but not least, RDE Type Behaviors have "Access Levels", which can define what operations can be done in that behavior.

Description

This PR adds 3 new resources and 3 new data sources:

• vcd_rde_interface_behavior resource to manage RDE Interface Behaviors, which can be invoked by RDEs and overridden by RDE Types.
• vcd_rde_interface_behavior data source to read RDE Interface Behaviors, so they can be used
  in RDE Type Behavior overrides.
• vcd_rde_type_behavior resource to manage Behaviors in RDE Types, which can override those defined
  in RDE Interfaces.
• vcd_rde_type_behavior data source to read RDE Type Behaviors.
• vcd_rde_type_behavior_acl resource to manage the access to Behaviors in RDE Types and RDE Interfaces
• vcd_rde_type_behavior_acl data source to read Access Levels from Behaviors of RDE Types and RDE Interfaces

Caveats

• Behaviors of a RDE Interface must be created before any RDE Type that uses that Interface is created. For that reason, if one uses vcd_rde_interface_behavior, she must be sure that the vcd_rde_type resources wait for the behaviors to be created with a depends_on. This is explained in vcd_rde_type resource and vcd_rde_interface_behavior resource documentation.

• vcd_rde_type_behavior_acl could have been a Set inside vcd_rde_type_behavior but it has some peculiar features that made it not possible:

  • An Access Level can be defined for a RDE Type that didn't override a Interface Behavior
  • For this reason one can use RDE Type Behavior IDs but also RDE Interface Behavior IDs.

• This PR does not implement RDE Type Hooks. As one Hook is a map of keys PostCreate, PostUpdate, PreDelete and PostDelete and values , I believe the best option is yet another resource, otherwise we'd have a circular dependency RDE Type (needs behavior IDs) <-> RDE Type Behavior (needs RDE Type IDs). Probably I'll do in a separate PR

[Didainius]

😵‍💫
At first sight I don't have much to complain, but this is so meta that I will make another review attempt later

[lvirbalas]

Awesome PR! Only few suggestions for docs.

[adezxc]

Approved, as Dainius said this is very meta, we might need a refresher on RDEs once again :D