icon_scaling.fields array to support different fields for icon scaling

[simon-leech]

Description

Much like hover / hovers and label / labels, it would be nice to have support for multiple fields to choose from when choosing the field to apply for proportional scaling icon_scaling.

This would just be a dropdown to choose for the user.

Type of Issue

Please delete options that are not relevant, and select all options that apply.

• ✅ New Feature