Add TCP/UDP DSL Specs [INT-4162]

**[Gary Russell](https://jira.spring.io/secure/ViewProfile.jspa?name=grussell)** opened **[INT-4162](https://jira.spring.io/browse/INT-4162?redirect=false)** and commented

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This issue is a sub-task of #8104

**Referenced from:** pull request https://github.com/spring-projects/spring-integration/pull/1966
