Link subflows to their parents and give them more meaningful names

[NTPape]

Currently it's almost impossible to find certain subflows in the overview because their name is just a random UUID. The only thing to go for right now is the processor IDs where the data went through which are only available when logging is set to 'all'.

It would be great if they were linked somehow to their parent flows and also have meaningful names, which could for example include the ID of the processor which kicked them off.

Maybe we could also store the used replacements per subflow in the Monitor as well.