Allow setting `cli_follow_urlparam` via a command line parameter

It should be possible to set the `cli_follow_urlparam` configuration variable via a command line option.

The AWS CLI is sometimes used in production environments and the like, where managing a configuration file is not preferred. Like many other AWS CLI configuration variables, it should be possible to set `cli_follow_urlparam` through a command line option like `--cli-follow-urlparam`.