createLDSTestWireAdapter does not work with GraphQL wire adapter

[mburr-salesforce]

The new LDS GraphQL wire adapter emits data in the shape { data: ..., errors: [ ... ] }. This prevents component authors from using createLDSTestWireAdapter, which assumes the standard LDS { data: ..., error: ... } shape for emitted values.

Proposal is to create a new createGraphQLTestWireAdapter function & corresponding class in src/adapters that understands both the different shape & the special format of GraphQL errors and provides utility methods for constructing values to emit.

The alternative is to have test authors use createTestWireAdapter and create the GraphQL shapes themselves.