16145 Use module.ScriptName to call Script API instead of PK

[arthanson]

Fixes: #16145

Changes the script api back to using the "module.ScriptName" instead of id (this is the way it was in NB3.x). The test was a bit of a mess to fix, the issue is the get_vars function in the Script class calls the python_class property which calls module_scripts on on the module - this tries to load the module which fails as the script doesn't actually exist on disk.

curl -X 'GET' \
  'http://localhost:8000/api/extras/scripts/testscript.NewBranchScript/' \
  -H 'accept: application/json; indent=4' \
  -H 'Content-Type: application/json' \
  -H "Authorization: Token 6f22af1129a164f92e4abdfa716cb54df9684f5e"

{
    "id": 3,
    "url": "http://localhost:8000/api/extras/scripts/3/",
    "module": 7,
    "name": "NewBranchScript",
    "description": "Provision a new branch site",
    "vars": {
        "site_name": "StringVar",
        "switch_count": "IntegerVar",
        "switch_model": "ObjectVar",
        "manufacturer": "ObjectVar"
    },
    "result": {
        "object_id": null,
        "name": "",
        "scheduled": null,
        "interval": null,
        "started": null,
        "completed": null,
        "data": null,
        "job_id": null
    },
    "display": "NewBranchScript (testscript)",
    "is_executable": true
}

[jeremystretch]

Could we retain the numeric PK form of the URL as well, as an alternative? That would be more consistent with the manner by which other objects in NetBox are referenced.

[jeremystretch]

Thanks @arthanson!