Add depth in matches

[Drarig29]

As Toornament does here https://developer.toornament.com/v2/doc/organizer_bracket_nodes, it would be nice to add depth in matches.

This number starts at 1 (the end of the bracket, aka. root of the tree) and the bigger it is, the closer it is from the start of the bracket, aka. leaves of the tree.

[PaulEvans8669]

In my opinion, simplest solution would be to build a dependency graph and number the graph entries from last to first in dependency order.
I'll have a look. Other solutions might apear while I work on it.

[Drarig29]

I don't know if I'd want to persist this information or only provide a way to compute such information with a get.bracketNodes() method.

I think I'd prefer the latter.

Same for #87 and maybe #86.