Rule S5853: Consecutive AssertJ "assertThat" statement should be chained

Implements RSPEC-5853.

In order to avoid false positive, we have to make sure that:

• Two assertThat are consecutive:

  // Compliant
  assertThat(someList).hasSize(3);
  doSomethingModifyingSomeList();
  assertThat(someList).contains("something");
  

• some method might not be relevant (extract, filter, usecomparator)

  // Compliant
  assertThat(X).usingComparator(...).containsAnyOf(...);
  assertThat(X).containsAnyOf(...);
  

  One solution could be to report only when there is one method call after the assertThat.