(PUP-3024) Add deltarpm_percentage and deltarpm_metadata_percentage to yumrepo

This patch adds deltarpm_percentage and deltarpm_metadata_percentage to the
yumrepo type.
Merge pull request #3400 from juniorsysadmin/deltarpm-percentages

(PUP-3024) Add deltarpm_percentage and deltarpm_metadata_percentage