Termpair

- Add ability to copy+paste using keystrokes (copy with ctrl+shift+c or ctrl+shift+x, and paste with ctrl+shift+v)
- Add a status bar to the bottom of the page
- Show terminal dimensions in bottom status bar
- Add toasts to notify user of various events
- Fix bug where connected browsers do not have their websocket connection closed when terminal closes, which makes it look like the terminal is still connected when it is not.
- Improve error messages, in particular if there is no server running
- Fixed bug where websocket connection is briefly accepted regardless of whether a valid terminal id is provided to `/terminal/{terminal_id}`. Instead of returning a JSON object with the TermPair version, a 404 error is now returned.
- [dev] migrate codebase to typescript
- [dev] use React functional component instead of class component for main application

- Fix server bug when using SSL certs (44)

- Ensure error message is printed to browser's terminal if site is not served in a secure context (39)
- Make default TermPair terminal client port 8000 to match default server port (38)
- Always display port to connect to in browser's connection instructions

- Change default sharing port to None due to difficulties sharing to port 80/reverse proxies
- Print port in web UI's sharing command

- Remove debug message from server

- Pin dependencies
- Change default sharing port to 8000 to match default server port