Add rule to check repeatability headers

[mikekistler]

The Azure API guidelines recommend:

☑️ YOU SHOULD support repeatable requests according as defined in OASIS Repeatable Requests Version 1.0.

This involves adding two header parameters, Repeatability-Request-ID and Repeatability-First-Sent, to an operation definition. Recently a service team did this (at our recommendation) but made a few mistakes in doing so.

• They specified x-ms-parameter-location: client on both parameters -- that is incorrect since the value of these headers should be set on each operation.
• They did not specify format: date-time on Repeatability-First-Sent.

We may also want to recommend format: uuid on `

The API guidelines also state:

When [the repeatability header is] understood, all endpoints co-located behind a DNS name MUST understand the header.

This might be another thing to check for.