[mlir][Transforms][NFC] `GreedyPatternRewriteDriver`: Use composition instead of inheritance

This commit simplifies the design of the `GreedyPatternRewriterDriver` class. This class used to inherit from both `PatternRewriter` and `RewriterBase::Listener` and then attached itself as a listener.

In the new design, the class has a `PatternRewriter` field instead of inheriting from `PatternRewriter`, which is generally perferred in object-oriented programming.