-Renamed GroupField to GroupFilter
- Moved GroupFilter from reports.fields to reports.filters.select
- updated references of reports.fields.GroupField to reports.filters.select.GroupFilter
- see commit b85e8f65939a33b607c26403f751230f86ce7263
- FilterUsersField is now UserTypeFilter in reports.filters.users
- changed all references in reports from FilterUsersField to UserTypeFilter
- moved templates around for UserTypeFilter and SelectMobileWorkerField into reports/filters
- see commit c5f8fdc6734a25d8e4c413768847db66dd524f2b