new rule: verify paging links only exist on collection routes (Section 6.6)

[marquje]

Per Section 6.6 of JSON:API v1:

The following keys MUST be used for pagination links:

first: the first page of data
last: the last page of data
prev: the previous page of data
next: the next page of data

Keys MUST either be omitted or have a null value to indicate that a particular link is unavailable.

A new rule needs to created to verify these link names only exist on collection routes.