Singleton resource do not work with separate client namespace

[timotheeguerin]

See the openapi3 emitter for client then route use {employeeName} instead of default

Playground Link

The problem is that we set this route resolution option on the namespace which is then not resolved in the client namespace.

[weidongxu-microsoft]

Currently, this is the last remaining blocker for SDK team to generate SDK directly from TypeSpec, for a relatively large brownfield (avs) service that already done the conversion to TypeSpec (and verified the result via Swagger and TypeSpec).