Do not block by default (#8580)

Currently, many timeouts in the project are like `-1` or other negative value
with a meaning to wait indefinitely.

According to distributed systems design and bad demo developing experience
it is not OK to block forever.

* Rework most of the timeouts in the framework to be `30` seconds.
Only one remained as `1` seconds is a `PollingConsumer` where it is
better to not block even for those 30 seconds when no messages in the queue,
but let the polling task be rescheduled.
* Remove the `MessagingGatewaySupport.replyTimeout` propagation down to the
`PollingConsumer` correlator where it was a `-1` before and blocked
the polling thread on the `Queue.poll()`.
This fixed the problem with a single thread in a pool for auto-configured `TaskScheduler`.
Now with 1 seconds wait time we are able to switch to other scheduled tasks
even with only 1 thread in the pool

spring-integration-http/src/main/resources/org/springframework/integration/http/config/spring-integration-http.xsd

@@ -498,7 +498,7 @@
 							]]></xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-					<xsd:attribute name="reply-timeout" type="xsd:string">
+					<xsd:attribute name="reply-timeout" type="xsd:string" default="30000">
 						<xsd:annotation>
 							<xsd:documentation><![CDATA[
 								Allows you to specify how long this gateway will wait for
@@ -515,9 +515,7 @@
 								The "reply-timeout" attribute maps to the "sendTimeout" property of the
 								underlying 'MessagingTemplate' instance (org.springframework.integration.core.MessagingTemplate).
 
-								The attribute will default, if not specified, to '-1', meaning that
-								by default, the Gateway will wait indefinitely. The value is
-								specified in milliseconds.
+								The value is specified in milliseconds.
 							]]></xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>