Provide 3 fixes for the diff plugin

[Rickmarges]

What does this PR do?

This PR contains 3 fixes for the diff plugin. I'll explain them one by one:

1. Usage access to instance_groups is removed:

When setting usage access to an instance_group (with {"role": "use", "instance_groups": ["Dummy instance group"], "user": "test@example.com"}) the diff plugin tries to remove it afterwards.
This is due to the API returning information in singular version, but as can been seen above, the role module requires the plural version.

From API:
{
  "users": [
    "test@example.com"
  ],
  "teams": [],
  "name": "Use",
  "role": "Use",
  "type": "role",
  "resource_type": "instance_group",
  "instance_group": "Dummy instance group",
  "user": "test@example.com"
}

Diff plugin creates:
{
  "role": "use",
  "instance_group": "Dummy instance group",
  "user": "test@example.com",
  "state": "absent"
}

Should be:
{
  "role": "use",
  "instance_groups": [
    "Dummy instance group"
  ],
  "user": "test@example.com",
  "state": "absent"
}

This is fixed by converting the singular versions into plural.

2. When explicitly setting state: present, the plugin creates a present and absent object in some cases

In some cases (I've seen it happen with organizations, but might happen with more) when someone explicitly sets state: present in configuration (compare_list) the diff plugin returns 2 items, one absent and one present state.

If compare list like this it works fine (no diff after first apply):
{
    "user": "test@example.com",
    "organizations": [
        "Dummy"
    ],
    "role": "admin"
},

If with explicit state present:
{
    "user": "test@example.com",
    "organizations": [
        "Dummy"
    ],
    "role": "admin",
    "state": "present"
},

Results in:
{
    "organizations": [
        "Dummy"
    ],
    "role": "admin",
    "state": "present",
    "user": "test@example.com"
},
{
    "organizations": [
        "Dummy"
    ],
    "role": "admin",
    "state": "absent",
    "user": "test@example.com"
},

This is fixed by changing the way the dicts are compared. A separate method is used where the state key is ignored.

3. Member rights to teams aren't removed

When a user should no longer be member of a certain team the configuration is removed. However, the diff plugin creates the wrong absent dict. Setting (or removing) membership access is done by using the target_team key, not team.

Created by diff plugin:
{
    "role": "member",
    "state": "absent",
    "team": "dummy-team",
    "user": "test@example.com"
}

Should be:
{
    "role": "member",
    "state": "absent",
    "target_team": "dummy-team",
    "user": "test@example.com"
}

This is fixed by checking if the team key is present and the role is member. If both are true, update the dict to change team to target_team.

How should this be tested?

Some items are automatically checked by the pipeline.
Otherwise tests can be performed based on the data provided in the code blocks above

Is there a relevant Issue open for this?

Other Relevant info, PRs, etc

[Rickmarges]

Will rebase after #721 is merged (I've changed the same line as in that PR)

[ivarmu]

Great catches! I think the else indentation seems to be wrong. Could you check this?

[ivarmu]

LGTM

[sean-m-sullivan]

Looks good to me, good additions, thanks!