Implement language-specific UST dump

[KvanTTT]

If we convert the following PHP code

$a->$b->$c

The following output from UST .ToString() we get:

a.b.c

It would be greate to use two modes: Universal and Specific for UST dump.

It can be used for more precise matching with PatternAny node.

Ideally it would be great to use full-fidelity UST trees.