feat(prowler): chk.002 multi-provider configuration

[Kakudou]

Goal

Provide a clear multi-provider configuration experience for Prowler.

PR Target

Prowler multi-provider configuration.

Gherkin Acceptance Criteria

Feature: Prowler multi-provider configuration

  Scenario: Select one supported provider
    Given a configuration with one supported provider
    When the configuration is accepted
    Then exactly that provider is selected

  Scenario: Select multiple supported provider
    Given a configuration with multiple supported provider
    When the configuration is accepted
    Then exactly those provider are selected

  Scenario: Reject a missing provider
    Given a configuration without a provider
    When the configuration is submitted
    Then the configuration is rejected

  Scenario: Reject an unknown provider
    Given a configuration with an unknown provider
    When the configuration is submitted
    Then the configuration is rejected

Done Checklist

• Support provider from AWS, Azure, GCP, or Kubernetes.
• Reject missing or unknown providers.