Node subtitle field that can be used to disambiguate nodes within node groups

[TheMartianLife]

Is your feature request related to a problem? Please describe.

When you have multiple nodes in a node group, they all have the same node title. This makes it difficult to trace or visualise node flow at the "specific node that was run/is running/should run" level.

Describe the solution you'd like

If a subtitle: field is present on all (or all minus one) nodes in a node group, debugging information and graph visualisation could distinguish each individual node in a node group by <title>_<subtitle>. For example:

title: Guard
subtitle: ArrowKnee
---
GUARD: I used to be an adventurer like you. Then I took an arrow in the knee...
===
title: Guard
subtitle: Disrespect
---
Guard: Disrespect the law, and you disrespect me.
===

If a crash happens while the second node is running, instead of saying "crash inside Guard" or "crash inside Guard_<UUID>", you could say "crash inside Guard_Disrespect". This could also be shown in the node group UI in the VSCode graph view - though I know the overall presentation of node groups here is still undecided.

Note: this does not mutate the title value, nor should it allow users to explicitly jump to a particular instance within a node group. This is purely for debug reasons, and also to bring the sense of descriptive node titles - that writers seem to make great use of - back into node groups. This should also assist users who are looking to examine or customise saliency.