JAMES-3596 Seperate maven modules for apps LDAP integration tests are not required

[chibenwa]

Addresses @jeantil remarks: #487 (comment)

The only thing that got me surprised was the choice to split

 - cassandra-app-ldap-tests
 -  cli-integration-tests
 -  distributed-ldap-tests

Away from their respective modules (if I understand this change correctly). It puts testing modules in the apps/assembly directory which I find counter intuitive even if they are clearly marked as being tests.

Can you explain the rationale behind the split ? I'm not opposed but I would like to understand the why as it breaks expectations, and maybe ask that the why be explained in a readme in the apps dir so that people proposing new assemblies or manipulating assemblies would know if they need to provide a test module too.

Regarding cli-integration-tests there is a circular dependency as we use server-cli as a runtime dependency....