first draft add of datasource for user grants

[dfry]

Adding this PR just to find out if this would be an acceptable addition to the provider.

Definition of Ready

• Short description of the feature/issue is added in the pr description
• PR is linked to the corresponding user story
• Acceptance criteria are met
• All open todos and follow ups are defined in a new ticket and justified
• Deviations from the acceptance criteria and design are agreed with the PO and documented.
• No debug or dead code
• My code has no repetitions
• All non-functional requirements are met
• The generic lifecycle acceptance test passes for affected resources.
• Examples are up-to-date and meaningful. The provider version is incremented.
• Docs are generated.
• Code is generated where possible.

[dfry]

@stebenz @hifabienne any feedback on this suggested feature? is this something you could see incorporating into your next release?

[stebenz]

Some questions about the content of the PR.

[stebenz]

Why is only the projectName used as a query? It is even listed as computed, I would rather use other identifiers first, and maybe provide the name later.

[dfry]

i am using projectName as the query because that is my current use case, i need to lookup the user grants by project name. Feel free to make it more generic or point me to an example of how you want it done.

[stebenz]

Sounds good to me for the start, normally I would at least add the identifier of the project itself as a base query.
Have a look at the application_saml resouce as an example.

[stebenz]

Please also include the necessary templates and examples to regnerate the documentation, as a reference have a look in the paths templates/resources/application_saml.md.tmpl, templates/resources/application_samls.md.tmpl, examples/provider/data-sources/application_saml.tf and examples/provider/data-sources/application_samls.tf.

Testing for the datasource is also missing, please refer for that to the application_oidc/datasource_test.go