Fix: Validate project_role

[liranfarage89]

Issue & Steps to Reproduce / Feature Request

While QAing #140 , @RLRabinowitz notice that on PR-Plan we don't validate the role.

Solution

validate it.

[avnerenv0]

TBH not loving this implementation,
Role should probably be a stronger type than string and also it's not the responsibility of resource_team_project_assignment to validate Role values, that should be in the model or similar.

However - not critical AT ALL so definitely approved 👍

[liranfarage89]

@avnerenv0
I've started something(very quickly), but the tests need to be changed, which is the most of work here.

how would you suggest handle that? opening a PR with "doing on the side"?

https://github.com/env0/terraform-provider-env0/tree/chore-move-role-validation (see the last commit)

[avnerenv0]

@liranfarage89

opening a PR with "doing on the side"?
Nah, if you wanna do it just go ahead and get it over with, not "on the side".
Just let our dev channel know that you want to complete this part, and keep an eye on the ROI of the task, if it get's messy probably leave it.

BTW we talked about breaking that model file into file-per-model, you might as well put Role in it's own file.

[liranfarage89]

@avnerenv0
that's ROI negative currently, that's why I thought about "doing on the side" 😕