[List] Change multiple icon or Add prop to support multiple icon types

[geospatialem]

Description

Before replacing the deprecated pick-list with the list, the selectionAppearance icon defaulted to a simple check.

For consistency with the previous structure of pick-list, we could either:

1. Change the multiple icon to be in line with the pick-list and add the "check" icon, or

2. Allow users select from a few differing options. Could be similar to the accordion's iconType prop.

pick-list (current and expected in list):

list (current):

Acceptance Criteria

Support the "check" icon when the list's selectionAppearance is set to and selectionMode is set to multiple.

Expected:

Relevant Info

Came up in a Community discussion on 3/14/23.

Which Component

list and list-item

Example Use Case

For testing/current use case: https://codepen.io/geospatialem/pen/WNgzByM

Esri team

Calcite (design)

[geospatialem]

Consider with #6700

[ashetland]

Closing in favor of #6700