Support cops on policyfiles in addition to cookbooks.

[Swathisivakumar]

What category of cop is this?:

Please try to select as few as possible.

• Chef/Deprecations - A cop that alerts on a deprecation in the Chef Infra Client
• Chef/Correctness - A cop that alerts when incorrect coding behavior is being used
• Chef/Sharing - A cop that alerts to missing functionality necessary for sharing cookbooks with others
• Chef/Style - A cop that alerts to a style best practice
• Chef/Modernize - A cop that alerts when a cookbook can be simplified or modernized with new functionality
• Chef/Effortless - A cop that alerts on code that must be resolved to move to the Effortless pattern
• Chef/RedundantCode - A cop that detects redundant code regardless of Chef Infra release

Describe the new cop:

This is a request for cookstyle to also support cops on policyfiles in addition to cookbooks.. ex: native cookbooks

What it would trigger on:

cookbook 'poise-hoist', '~> 1.2'
            or
run_list ['poise-hoist']

[Swathisivakumar]

#351 - we want this to be applied to all deprecated and moved-into-client cookbooks, but checking in the policyfiles.