`@body body: bytes` should produce `format: binary` not `format: bytes`

[timotheeguerin]

Current having a response like

model Response {
  @contentType: "application/octet-stream";
  @body body: bytes;
}

Should produce

content: 
  application/octect-stream:
    schema: 
       type: "string"
       format: "binary"

fix in:

• openapi3 Fix binary request & response openapi #125
• cadl-autorest https://github.com/Azure/cadl-azure/pull/1065

[markcowl]

should be closed when https://github.com/Azure/cadl-azure/pull/1065 is merged