Add no-store to the Cache-Control header on auth responses

[JackLewis-digirati]

Related to #833

This PR adds a Cache-Control header of no-cache,no-store to the following endpoints:

• auth/{customer}/clickthrough
• auth/{customer}/token
• auth/{customer}/{authService}
• auth/{customer}/{authService}/logout

This should help to avoid issues where auth responses are cached incorrectly

NOTE: this header has not been added to auth/v2/probe/{customer}/{space}/{image} as this resource already has a Cache-Control value of private

[donaldgray]

As the issue that we encountered is related to the AccessTokenResponse - is it worth adding tests to confirm the appropriate headings are set there? Would pick up if the attribute was somehow removed

[garyttierney]

Btw, no-cache,no-store is equivalent to no-store https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control#use_cases

[JackLewis-digirati]

should be changed to use just no-store - thanks Gary