Disable DB init for JDBC Source and Sink (#325)

* Disable DB init for JDBC Source and Sink

The `IntegrationAutoConfiguration` provides mechanism
to initialize DB with some out-of-the-box scripts.
The default behavior is `EMBEDDED` even if we don't use
any components for those DB objects, e.g. no `JdbcMessageStore` bean.

* Add `spring.integration.jdbc.initialize-schema=NEVER` to the
`jdbc-consumer` and `jdbc-supplier` to not attempt to initialize DB
* Fix Checkstyle violations in other modules

function/http-request-function/src/main/java/org/springframework/cloud/fn/http/request/HttpRequestFunctionConfiguration.java

@@ -23,7 +23,6 @@ import java.util.function.Function;
 import reactor.core.publisher.Flux;
 
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.boot.web.reactive.function.client.WebClientCustomizer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.HttpHeaders;