Prior to this commit, if attributes were configured in the builder
returned by `ServerRequest.from(...)`, those attributes were not
available in the `ServerRequest` built by the builder. In addition, any
attributes in the original `ServerRequest` supplied to
`ServerRequest.from(...)` were also ignored.
This commit addresses this issue by ensuring that the attributes
configured via DefaultServerRequestBuilder are used as the attributes
in the resulting `ServerRequest`.
This commit also polishes the Javadoc in `ServerRequest` and
`ClientResponse` and avoids the use of lambda expressions in the
constructors for `DefaultServerRequestBuilder` and
`DefaultClientResponseBuilder`.
Closes gh-25106
5c04c96d0e