[List Item]: add icon-end/start props

[ashetland]

Check existing issues

• [X] I have checked for existing issues to avoid duplicates

Description

List Item should match other similar components in this regard and include properties for icon-end and icon-start. This would improve the OOTB experience when adding icons to list items vs the current workflow of relying on using the content slots.

Acceptance Criteria

• [ ] icon-end
• [ ] icon-start

Relevant Info

No response

Which Component

List Item

Example Use Case

No response

Priority impact

p4 - not time sensitive

Calcite package

• [X] @esri/calcite-components
• [ ] @esri/calcite-components-angular
• [ ] @esri/calcite-components-react
• [ ] @esri/calcite-design-tokens
• [ ] @esri/eslint-plugin-calcite-components

Esri team

Calcite (design)

[ashetland]

cc @driskull