adding empty interace to allow any value to parsed to it

[pmmalinov01]

What type of PR is this?

Bug

What this PR does / why we need it:

To allow more values to be passed to the on-premise service desk request

Which issue(s) this PR fixes:

Fixes #647 https://github.com/andygrunwald/go-jira/issues/647

Special notes for your reviewer:

I am coming for from an operations perspective and my go skills are not the best. I will try to change/adapt anything you suggest

Additional documentation e.g., usage docs, etc.: