OAuth2 Jinja Configuration

This release adds a new jinja variable called initOAuth.

This allows the server to pass configuration to the initOAuth() call in swagger-ui. Kudos to @m-agel for the idea.

render_template(
    'index.j2',
    initOAuth={
        'clientId': 'my-swagger-ui',
        'usePkceWithAuthorizationCodeGrant': True,
    }
)