v0.7.1 - The data-tab-nav "incident"

This patch release fixes a small, but annoying Wagtail 2.13 incompatibility which made it impossible to use the tabbed interface in the chooser modal. Between 2.12 and 2.13, Wagtail tweaked a bit how it handles tabs in order to accomodate new features, as well as tidy up old code. all we needed was a good old data-tab-nav for the chooser tabs.

Thank you @jams2 for the sleuthing and PR 🕵️‍♂️