Add OAUTH authentication option to SMTP servers

[lucymcphail]

This patch leaves the auth argument to smtp_server as it is, but adds a new token_auth block to let users configure an auth token through Terraform.

Implements #1162

[lucymcphail]

I've tested this locally and everything seems to work, except the ConflictsWith on auth and token_auth: Terraform seems happy to allow both of them to exist together, so I suspect something's wrong with the attribute paths, but I'm not sure what.

[lucymcphail]

Looks like the ConflictsWith was actually working fine all along, I think something must have been doing something wrong with my testing. Should be ready to review now.

[thomasdarimont]

Thanks for your PR.

I updated your branch, accidentially pressed merge main instead of rebasing it on main. Feel free to rebase the branch on your side on latest main, then we can see if we can. integrate it this week.

[thomasdarimont]

Just saw the PR #1266, which overlaps a bit with this PR. How about integrating #1266 first and adding this PR after?

[thomasdarimont]

Please ignore what I said in ... #1293 (comment) :)

Would it be possible to add 2 additional test-cases similar to the following examples?

• https://github.com/keycloak/terraform-provider-keycloak/blob/main/provider/resource_keycloak_realm_test.go#L114
• https://github.com/keycloak/terraform-provider-keycloak/blob/main/provider/resource_keycloak_realm_test.go#L135

[lucymcphail]

Rebased onto main, and I've added those test cases. Let me know if there's anything else we need :)

[thomasdarimont]

Thanks @lucymcphail! I'll take it from here and try to get this merged this week.

[thomasdarimont]

Thanks for adding the tests. I just gave this a spin. Looks good to me :)

I'll retrigger the build and merge if it passes.

This also fixes #1194.