Limit maximum size when pulling manifest and config

[kostko]

It seems like there is currently no easy way to set limits on the maximum allowed size of the manifest and config in when invoking pull_manifest_and_config. This is useful in case pulling images from untrusted sources that could provide arbitrary long responses.

[thomastaylor312]

You are entirely correct. We should probably allow for some configurable options. We might want to rewrite the client to have a builder method that lets you set the various options we've accumulated over the years