Release v4.20.0

Chat topic lists can offer per-topic actions, and applications no longer need to install tsyringe themselves.

Added

• ChatTopicList and ChatSidebar accept topicActions: labeled buttons next to each topic, such as Rename, Pin or Archive, with an optional isAvailable check per topic. Each button's accessible name includes its topic, the buttons can be reached with the keyboard, and activating one does not open the topic. When an action hides itself or removes its topic, focus moves to that topic, to the topic that took its place, or to New topic, unless your handler already moved focus. ChatSidebar's existing actions prop still means message actions. Topics without actions render as before. The ChatTopicAction type is exported. (#206)

Changed

• tsyringe is now an optional peer. Components never imports it, and Arc React installs it as its own dependency, so you no longer need to install it yourself. reflect-metadata stays a required peer: keep installing it and importing it at your entry point. The package check now fails if a published file imports either package. (#248)

Closes #206, closes #248.