Add computed output field to get the latest cloned version by the provider

[philippschulte]

This allows users of the provider to get the latest cloned version by the provider. If the activate field is set to false and the plan output shows changes then the values of active_version and cloned_version are actually different after applying them otherwise, the values are the same. The value of cloned_version is only available after running the terraform apply command. Here are some examples after applying:

1. Brand new service:

fastly_service_v1.demo: Creating...
fastly_service_v1.demo: Creation complete after 18s [id=5wzq2Rcc7rEg2H6s1AJGdU]

Apply complete! Resources: 1 added, 0 changed, 0 destroyed.

Outputs:

active_version = 1

2. Updating existing service (activate = true)

fastly_service_v1.demo: Modifying... [id=5wzq2Rcc7rEg2H6s1AJGdU]
fastly_service_v1.demo: Modifications complete after 24s [id=5wzq2Rcc7rEg2H6s1AJGdU]

Apply complete! Resources: 0 added, 1 changed, 0 destroyed.

Outputs:

active_version = 2
cloned_version = 2

3. Updating existing service (activate = false)

fastly_service_v1.demo: Modifying... [id=5wzq2Rcc7rEg2H6s1AJGdU]
fastly_service_v1.demo: Modifications complete after 25s [id=5wzq2Rcc7rEg2H6s1AJGdU]

Apply complete! Resources: 0 added, 1 changed, 0 destroyed.

Outputs:

active_version = 2
cloned_version = 3

[thommahoney]

💯 thanks