update to latest provider extensions

[matt-beanland]

The instance extension has evolved (structure/behaviour) and now supports some create functionality such that custom create:build may not be necessary.

There is also a place and party extension, these should be used.

This isn't a pure refactor as DSL has changed and ActionHelpers have been removed. For maintaining Assigner related functionality there are methods on the extended instance.

[matt-beanland]

All instance resources have been migrated to the diffo 0.3.0 structure do / behaviour do DSL. ActionHelper has been removed throughout — build lifecycle wiring is now handled globally by the framework. RSP has been updated to the revised BaseParty API (type: :Organization replacing :kind) and declares its owned resource types via the Party Extension instances do block.

The initializer no longer seeds specifications eagerly — they are created lazily by build_before as of 0.3.0.

Tests updated for two 0.3.0 output changes: referred_type (snake_case) in place and party creation, and a description field now emitted in instance JSON from the specification. All 49 tests + 4 doctests pass.

One known issue: VerifyRoles in the Party Extension groups duplicate-role checks by role name alone, which incorrectly flags the RSP instances do block where the same role (:owner) is legitimately declared for multiple instance types. The correct unique key is {role, party_type}. Fix is deferred to diffo#101 — the verifier path will change when Party and Place extensions gain the structure do wrapper, so patching it now would just be superseded