Format styles dropdown does not show the currerntly active selection

[mscherr-fastspot]

Description

Related to #246 which was closed by the original author.

The format dropdown does not highlight the format (if applicable) of the currently selected text:

Cursor is currently on the H2 behind the dropdown

In the documentation for Imperavi (linked from this repo) for the "Format styles", this functionality works by adding an active class to the dropdown element:

This functionality does not seem to be in the Craft plugin.

Steps to reproduce

1. Select any text that relates to a format option in the editor
2. Notice that the active format is not visually shown in the format dropdown, as shown in the Imperavi link.

Additional info

• Craft version: 4.8.0
• PHP version: 8.2
• Database driver & version: MySQL 8.0.33
• Plugins & versions: Redactor 3.0.4