Message Groups

[craigrileyuk]

Allow messages to be assigned a group, which condenses those messages into a single displayed one with a badge denoting the number in that group.

• [x] Add a group prop to the component to enable the feature
• [x] Implement group functionality when processing the stack
• [x] Create badge component to display the number in that group

[craigrileyuk]

Resolved with v1.1.0