Add initial mock tests examples and pipelines

[arnaudlh]

1949

Closing 1949.

Summary

This pull request includes several changes to improve the testing workflows and documentation of the project. The most significant changes include the addition of new GitHub workflow files for dispatching pull requests and running tests, modifications to the instructions for running workflows locally, and the introduction of Terraform test commands.

Outline

GitHub workflows:

• .github/workflows/pr_dispatch.yaml: Added a new GitHub workflow for dispatching pull requests. This workflow triggers on pull request events and runs a job that dispatches a repository event with a client payload containing the scenario to run.
• .github/workflows/pr_workflow.yaml: Added a new GitHub workflow for running PR tests. This workflow triggers on repository dispatch and workflow dispatch events, and runs jobs to load test scenarios, run mock plan scenarios, perform Terraform integration tests, and purge the integration environment if the previous jobs fail or are cancelled.

Terraform test commands and mock data:

• examples/tests/README.md: Added documentation for running Terraform test commands locally.
• examples/tests/general.tftest.hcl: Added a new Terraform test file with mock providers.
• examples/tests/mock/e2e_plan.tftest.hcl: Added a new Terraform test file for end-to-end plan testing with mock providers.
• examples/tests/mock_data/data.tfmock.hcl: Added a new Terraform mock data file for the azurerm_client_config and azuread_client_config data sources.

Local configuration:

• locals.tf: Modified the client_config local to use the tomap function instead of the map function.

Documentation:

• .github/workflows/developer.md: Improved the instructions for installing Act and running GitHub workflows locally, including the addition of a link to the Act GitHub repository and the use of the gh auth token command to authenticate with GitHub.