Remove report types 'assessment' and 'conference_paper'

[amruelama]

There are currently 40 'assessment' type reports and 1 'conference_paper' stored in GCIS.

• [x] Change type 'assessment' to type 'report'
• [x] Convert type 'conference_paper' to generic
• [x] Remove type 'assessment and 'conference_paper'

[lomky]

@amruelama I added the route so you can control report types!

https://data-stage.globalchange.gov/report_type

You should be able to delete any type that isn't being used by a report.

[amruelama]

@lomky Thank you!