Make creating parser/lexer/etc sequence easier

To create a parser, you have to create about 5 different objects, most of which are not referenced again. That's quite cumbersome. Maybe a `*Recognizer` class could be generated which automatically creates the `*Parser`, `*Lexer`, and `CommonTokenStream`, and provides accessors for them, in case you need them.

No files, tests, or entry points are identified in the issue. Start by locating how the Parser, Lexer, and CommonTokenStream are currently created and determine how a generated Recognizer could expose them; done means a simpler creation sequence with accessors for those objects.

Written by the indexing model from the issue text.