java.net.http.HttpClient should reset the stream if response headers contain malformed header fields

The current behavior is to close the connection with a protocol error.

According to RFC 7540:

Endpoints MUST treat a request or response that contains
undefined or invalid pseudo-header fields as malformed (Section 8.1.2.6).

Also:

Just as in HTTP/1.x, header field names are strings of ASCII
characters that are compared in a case-insensitive fashion. However,
header field names MUST be converted to lowercase prior to their
encoding in HTTP/2. A request or response containing uppercase
header field names MUST be treated as malformed (Section 8.1.2.6).

Section-8.1.2.6:
 Malformed requests or responses that are detected MUST be treated as a stream error (Section 5.4.2) of type PROTOCOL_ERROR.