AbstractClassRestrictionsSniff sniffs: add tests for namespaced names

[rodrigoprimo]

Description

In preparation for PHPCS 4.0, which changes the tokenization of namespaced names, this PR adds tests with all forms of namespaced function calls (partially qualified, fully qualified, and namespace-relative using the 'namespace' keyword) as well as fully qualified global function calls to the sniffs that extend the AbstractClassRestrictionsSniff class when necessary. Some test files already contained part or all of the required tests.

For DeprecatedClasses, I opted to add the tests in a separate file as the error lines DeprecatedClassesUnitTest.1.inc are generated dynamically. Since the tests were added to a separate file, I opted to include all possible namespace variations even though a few already exist in DeprecatedClassesUnitTest.1.inc. I didn't want to complicate things by having the namespaced names tests in different files.

Suggested changelog entry

N/A

[rodrigoprimo]

Moved to draft pending the review of #2620

[rodrigoprimo]

@jrfnl, this PR is now ready for review. I implemented the changes that we discussed for #2620. I also removed tests for CapitalPDangit and added tests fro RestrictedClasses. This way this PR is now about namespaced names tests for sniffs that extend AbstractClassRestrictionsSniff.