Feature: support user creation (not invite user)

[mefellows]

The pact_user uses the "invite user" flow and only works for Pactflow Cloud, not the on-premises edition.

Pactflow has recently released SCIM, including a new POST endpoint to pre-create users in the database, with the appropriate IDP information, that doesn't rely on the "user invitation" workflow.

This allows for the following capabilities/use cases:

• Pre-creating users for integration with SAML 2.0 providers, allowing users to be given the appropriate role/team in advance
• Support for both on-premises and cloud Pactflow accounts

This feature requests a new resource pact_user_v2 which uses the new endpoint.