Internal error registry per package

[bmoylan]

Replace global conjure-type error registration with a generated registry per conjure definition.

Creates a new internal/conjureerrors package in each output directory for conjure definitions that include errors. Generated client implementations provide the definition-specific registry as a ConjureErrorDecoder to be used when deserializing a non-2xx JSON response.

Clients will no longer be able to deserialize errors not defined in their own conjure definition.

Generating multiple IRs into the same output directory will result in all definitions sharing the same error registry.

Requires palantir/conjure-go-runtime#724

Addresses #415

---

This change is 

[changelog-app]

Generate changelog in changelog/@unreleased

What do the change types mean?

• feature: A new feature of the service.
• improvement: An incremental improvement in the functionality or operation of the service.
• fix: Remedies the incorrect behaviour of a component of the service in a backwards-compatible way.
• break: Has the potential to break consumers of this service's API, inclusive of both Palantir services
  and external consumers of the service's API (e.g. customer-written software or integrations).
• deprecation: Advertises the intention to remove service functionality without any change to the
  operation of the service itself.
• manualTask: Requires the possibility of manual intervention (running a script, eyeballing configuration,
  performing database surgery, ...) at the time of upgrade for it to succeed.
• migration: A fully automatic upgrade migration task with no engineer input required.

Note: only one type should be chosen.

How are new versions calculated?

• ❗The break and manual task changelog types will result in a major release!
• 🐛 The fix changelog type will result in a minor release in most cases, and a patch release version for patch branches. This behaviour is configurable in autorelease.
• ✨ All others will result in a minor version release.

Type

• Feature
• Improvement
• Fix
• Break
• Deprecation
• Manual task
• Migration

Description

Replace global conjure-type error registration with a generated registry per conjure definition.

Creates a new internal/conjureerrors package in each output directory for conjure definitions that include errors. Generated client implementations provide the definition-specific registry as a ConjureErrorDecoder to be used when deserializing a non-2xx JSON response.

Clients will no longer be able to deserialize errors not defined in their own conjure definition.

Generating multiple IRs into the same output directory will result in all definitions sharing the same error registry.

Check the box to generate changelog(s)

• Generate changelog entry

[bmoylan]

Do not merge; requires palantir/conjure-go-runtime#724

[tabboud]

Couple notes but otherwise this looks good to me:

• Not being able to deserialize errors not defined by a Clients conjure definition seems more than reasonable, and in fact maybe more correct.
• It is common for projects to generate all conjure into a shared output directory, but this would be a good reason to push projects into namespacing their conjure dependencies, which I have found to be a better UX anyways. Besides this behavior would be the same as what currently exists and would not require a migration for users to pick this up.

[autorelease3]

Released v6.63.0