Add statement jump to_label if node emited_signal

[Jeremi360]

Now I'm working on VisualNovelKit,
and I wanted to add jump label_name if AnimatedNode finished as part of VisualNovelKit#169,
But first it is impossible to add_custom_regex() that use jumps to RkScript,
Second it will be better if you can use it with any node and singal combo.

This is how it will look in RakuScript:

node_path = "path/to/node/from/scene/root"
jump label_name if node_path signal_name