Redesign invalid node indicator

[webfiltered]

Invalid node redesign

• Uses node "type" as a fallback title
• Removes headache-inducing hard-coded error colour

Configurable

Prefer orange?

LiteGraph.NODE_ERROR_COLOUR = "#d61"

Old indicator + title

LiteGraph.use_legacy_node_error_indicator = true

Continues to be highly visible on busy workflows, even fully zoomed out:

API

• Renames drawSelectionBounding => strokeShape
• Extends the API to include thickness & colour
• Fixes scaling of padding with rounded corners:

[huchenlei]

Can you rebase this PR and explain why the node corner renderering changes?

[webfiltered]

Rebase: Done

Corners: So that's due to what is now ab83046. The previous setting was to simply double the rounded edges, which was close enough for what it was used for before - 6px. Math was was only off by 2px.

When you go up to 16px padding from the edge, it starts to look weird - the rounded corner is still the same as it was. With the new method, you get perfect alignment:

Edit: Added a side-by-side comparison to the mention in the PR.