Support models removed outside the plan.

[juanmanuel-tirado]

Description

When a model is removed manually, the terraform plan should recover and detect this situation. Added a specific error type to be processed.

Fix #222

Type of change

Please mark if proceeds.

• New resource (a new resource in the schema)
• Changed resource (changes in an existing resource)
• Logic changes in resources (the API interaction with Juju has been changed)
• Test changes (one or several tests have been changed)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Other (describe)

Environment

• Juju controller version: 3.2.0
• Terraform version: 1.3

QA steps

Follow the steps described in #222