Added the possibility to filter getSite requests in SiteService according to what the API provides

[marsv024]

We are in need to filter getSite requests using the filters provided by the API. I added the filtering options to Site Service, however I'm unsure on how to implement a test for this. I could not find any previous tests for the getSites method, getUserSites method or getAdminSites method to use as a template. Please advise on how to proceed or if this commit is good enough.