Update for use with Textual 0.9.1

[castaway]

Description:

Codebase / User Interface now runs with Textual 0.9.1 release and Bluetooth Numbers 1.0.0
No functional changes to the interface

Checklist:

• The pull request is done against the latest development branch
• Only one feature/fix was added per PR and the code change compiles without warnings
• I accept the DCO.

[castaway]

WIP / Draft because: The table view does not currently scroll up/down when using the mouse wheel. Does it on the older version of Textual? If so I think I probably need to swap the main ScrollView / Table for Container / DataTable, which is a subclass of ScrollView. (ScrollView itself is no longer exported as a main Textual widget)

[koenvervloesem]

Hi, thanks for this effort! Have you taken a look at the code of humble-explorer? I used a DataTable there instead of a ScrollView. Scrolling works that way. I also had to create the BleakScanner object in the app's on_mount method to be able to run it on macOS (koenvervloesem/humble-explorer#27).