[make:*] add ability to generate tests

[jrushlow]

This feature is experimental - generated code is likely to change significantly between point releases.

Adds the ability to pass --with-tests to make:registration, make:reset-password, & make:crud and maker will generate a new PHPUnit test tailored for the specific functionality of that maker. If --with-tests is not passed as an argument, MakerBundle will ask the user Do you want to generate PHPUnit tests? [Experimental].

This PR introduces a new internal CanGenerateTestsTrait that can be added to any Maker command. The method naming is intended to be intuitive - e.g. configureCommandWithTestsOption() should be called from configureCommand(), interactSetGenerateTests() called in interact(), & shouldGenerateTests() is used in the generate() method in a conditional to determine if the command should generate test code.

The userland tests we generate are run against the code generated by their respective makers in our test suite. This should be the case for any tests created going forward.

The tests are created under the App\Tests namespace and created in the tests/ dir. Possibly in the future we can customize this behavior - but for now - attempting to guess the correct test dir structure && keep everyone happy is outside the scope of this PR 😜

• make:reset-password
• make:registration
• make:registration w/ VerifyEmail
• make:security:form-login - PR [make:security:form-login] add ability to generate tests #1515
• make:crud - refactor to use canGenerateTests trait
• make:controller - Diff PR
• ensure we handle Verifying mail signature failed on prod SymfonyCasts/verify-email-bundle#149 if able - outside the scope of this pr