misc context | cache fixes

[lolopinto]

follow-up to #1635

• use context in a few places that were missing e.g. operations.ts
• consolidate types in one place
• add join to cache.QueryOptions and what it's checking
• use loader factory instead of loader in a bunch of tests so it's similar to production use cases
• clear out as many manual cache clearing as possible. if the cache has to be manually cleared, it's a sign that something is broken and fixed it e.g. missing context or context not threaded through
• probably more

may be worth doing a breaking change to make Context required but cache can be optional to imrp