Add method to integrate BaseQueryParser with Encoder

[efinder2]

I suggest to add this method to simplify the usage with the Encoder::withIncludedPaths. If this change is accepted I'll update the wiki accordingly

[efinder2]

I don't know how to fix the unused variable $parsed. Any ideas?

[neomerx]

        foreach ($aIncludes as $path => $parsed) {
            \assert($parsed !== null);

            yield $path;
        }

[neomerx]

I'm OK with the idea of adding a new method. Please push to issue243 branch as a single commit with comment 'Close #243'