Toolkit V3 tasks

[MrDinsdale]

Here's a list of potential changes for the Toolkit V3 release based on discussions we've had over the last few months.

Core

• [ ] Break settings into theme and settings to align with the design system. (See #532)
• [ ] Update values to align with design system.
• [ ] Theme should include breakpoints, colors, gradients, radius, shadow, spacing, typography.
• [ ] General clean up in core structure to organise functions and mixins.

UI

• [ ] Investigate which components should be flagged as legacy/deprecated and which should recieve on going maintainance.
• [ ] Update to match updated values in core.
• [ ] Update component styling to align with design system for non-legacy components.

General

• [ ] Investigate migrating to dart-sass for improved feature set. Native support for map-get($map, $key, $nested-key) and sass modules.
• [ ] Introduce modules and namespacing?
• [ ] Flatten Toolkit to a single package?

Had a play with dart and modules in a repo here