feat: add OAuth2 Password endpoint requiring two scopes

[2ynn]

GEN-1751

1. This PR adds an endpoint that requires both products:read and products:create scopes to be requested. This will help test the following scenario in https://github.com/speakeasy-api/openapi-generation/pull/3161 :

• create a product -> request a token with scope products:create
• update a product -> request a token with both products:create and products:read
• list products -> only products:read is required so reuse the last token received

2. Set the ExpireIn to 2min for the token returned by the /clientcredentials/token endpoint so that we can test reusing a valid token when required scopes have already been requested