Model Resource Completers in a single module

## Description
Model completers for
- [ ] Resource Group
- [ ] Resource Reference
- [ ] Resource Name
- [ ] SubscriptionId (use context cmdlets completer as a guide)
- [ ] Location

## Cost : 6

Locate the existing context cmdlets completer and use it as the guide for the SubscriptionId work. Then identify where resource completers are modeled and group the Resource Group, Resource Reference, Resource Name, SubscriptionId, and Location completers in one module. Done means all five checklist items are implemented and their completion behavior is covered by the relevant existing tests.

Written by the indexing model from the issue text.