Add Application, ServicePrincipal, Role, Group, RoleAssignment support

[vaspahomov]

Description of your changes

Add support of:

• Application
• ServicePrincipal
• RoleAssignment

This patch allow:

• Create Applications
• Create ServicePrincipal
• Assign roles on ServicePrincipal
• Assign roles on AD groups

I have:

• Read and followed Crossplane's [contribution process].
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

• Unit tests
• Manually tested

[ulucinar]

Hi @vaspahomov,
Thank you for the PR. I have left some comments. Could you please also mention in the PR description how you tested these new MRs?

[ulucinar]

Should we make this part of the spec (i.e., make it a parameter)?

[vaspahomov]

I think better to implement creds autoupdates, I added todo note about this

[vaspahomov]

Hi! @ulucinar
I've commit fixes

[lovelinuxalot]

Any updates when this PR is getting merged?

[ulucinar]

Hi @vaspahomov,
Could you please check the failing tests?

[vaspahomov]

Hi @ulucinar,
Removed unused code in tests

[ulucinar]

Hi @ulucinar, Removed unused code in tests

Thank you very much @vaspahomov for bearing with us on this PR. Together with @sergenyalcin, we took another pass over the PR. Among the resolved issues, I did not fully understand the logic here:
https://github.com/crossplane/provider-azure/blob/6c8e8ee885d8d1867992df56902aa1aa49f862c1/pkg/controller/rbac/application/managed.go#L105
or,
https://github.com/crossplane/provider-azure/blob/6c8e8ee885d8d1867992df56902aa1aa49f862c1/pkg/controller/rbac/serviceprincipal/managed.go#L84

Could you please shed some light on these probably with comments?

[goober]

Do I understand correctly that this change uses the Active Directory Graph API for communication with Azure?

If that is the case it should be noted that those API:s are deprecated and support will be removed on June 30th, 2022.
https://techcommunity.microsoft.com/t5/azure-active-directory-identity/update-your-applications-to-use-microsoft-authentication-library/ba-p/1257363

[mikebollandajw]

we are in need of this