Update SDK to OpenAPI spec (#899)

## Changes
<!-- Summary of your changes that are easy to understand -->
There are some backwards incompatible changes around cluster library
structs -- they needed to be fixed in library utils. Done those in this
PR also.

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->

- [ ] `make test` passing
- [ ] `make fmt` applied
- [ ] relevant integration tests applied

.codegen/_openapi_sha

@@ -1 +1 @@
-94684175b8bd65f8701f89729351f8069e8309c9
+21f9f1482f9d0d15228da59f2cd9f0863d2a6d55