As a user I want to be able to specify types of RPMs to skip during a repository sync

[ajsween]

The REST API for the Pulp RPM Plugin documents a parameter for "skip_types" that is not available via the pulp-cli wrapper. This is a very valuable filter because it allows skipping source RPMs in dnf repositories. Source RPMs tend to be many times larger than their respective compiled RPMs and take up significant space with very little return. When using Pulp to fully mirror a repository, the sync process often times out due to a default timeout of 5 minutes for any given operation. A single source RPM, for example, in the Appstream subscription for Oracle Linux 8 can be as large as 5 GBs.