Add api point that can return text body with a specified size, less than 5MB
Add api point that can return text body with a specified size, less than
5MB

[#107340756] ***[spike]*** Explore writing a CATSs test for MTU *[timebox, .5d]*

Signed-off-by: Difan Zhao <d4b657a67385123ddb690ebdb0d79b9c6cd38927@pivotal.io>

matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests,matt-royal/cf-acceptance-tests