2310 datasets v3 transition

[adrian-lara]

Any background context you want to provide?

Part of the effort to move FE and tests to v3 APIs

What's this PR do?

Update tests and frontend _services to use API v3 dataset endpoints

How should this be manually tested?

• On the dataset list page, CRUD datasets
• On the dataset detail page, CRD import_files
• On the inventory detail meter page, upload GreenButton data, see a list of datasets
• On any page, expand the left menu to view the count of datasets

What are the relevant tickets?

#2310

[coveralls]

Coverage remained the same at 69.166% when pulling 7ca2b03 on 2310_datasets_v3_transition into d97ce5c on develop.

[macintoshpie]

Looks great 👍

One note though, looking at the original issue it seems like we dont want to actually delete datasets (ie ImportRecords) when hitting the delete endpoint. But it looks like it's actually deleting them

EDIT: I was mistaken! Things work as expected. TIL about django's model Managers