Theme the menu local actions using Bootstrap's icons

In the core Drupal themes, the menu local actions are displayed inline and prefixed with a plus sign. See the screenshot below for an example of what they look like in Bartik.

In the Bootstrap theme, they are un-styled and displayed in a normal unordered list. See the screenshot below for an example of what they currently look like:

For consistency with how other themes style local actions, I propose that this theme display the links inline and use Bootstrap's icons to achieve it's look and feel while maintaining the Drupal specific UX of local actions.