Implements support for #[\Codeception\Attribute\DataProvider], #[\Codeception\Attribute\Examples] and @example annotation in unit tests.
Drops support for #[\PHPUnit\Attribute\DataProvider], @backupGlobals, @backupStaticAttributes, @preserveGlobalState and @testwith annotations.

I reused new DataProvider class is Cest Loader.

New possibilities:

• Unit format can use private method as data providers
• Cest format can use data provider methods from other classes.