NickAkhmetov/HMP-540/Update get_view_config_builder to use get_assaytype instead of get_assay

[NickAkhmetov]

This PR adds support for the assaytype endpoint instead of get_assay. This is a breaking change which requires revisions to support, so it is accompanied by a minor version change (to v0.1.0)

I validated the functionality of each builder using a local portal instance (using the branch hubmapconsortium/portal-ui#3361); each visualization appeared to work as expected when pointed at prod data. I have also updated the tests and fixtures accordingly to reflect the new interface.

TODOs from December 14

• Image pyramid visualizations are functional
• I have identified UUID's for datasets that trigger each of the given assaytype builders and created assaytype fixtures corresponding to those UUID's
• I updated the other "good" test fixtures' UUIDs to match the identified entities
• still need to debug the "good entity" tests and get them to actually pass
• still need to come up with a strategy to handle the "bad entity" tests

TODOs from December 12

• Troubleshoot seqfish image pyramid display
• update current uses of get_assay within portal-visualization

[john-conroy]

Looks great! We touched upon it briefly, but should we use the prod ingest url?