feat(simple_menu): Make scroll buttons configurable

This introduces a config flag to make the right buttons scrollable. I wasn't sure if I should just remove the old option in SimpleMenu but left it for backwards compatibility. If the config is set, it overwrites the SimpleMenu option.

I tested it with the main menu and the menu in the ecg app.

Fixes #204 (closed)

Documentation/card10-cfg.rst

@@ -48,4 +48,6 @@ Option name        Type       Description
 ``ble_mac``        Boolean    MAC address used for BLE. Format: ``ca:4d:10:xx:xx:xx``.
 ------------------ ---------- -----------
 ``ble_log_enable`` Boolean    Activate HCI level logging of BLE data. Creates a new btsnoop compatible log file named ``ble.log`` in the ``logs`` folder after each boot if BLE is activated. Keeps the last 10 files.
+------------------ ---------- -----------
+``right_scroll``   Boolean    Use both right buttons to scroll up and down. Lower left button is SELECT.
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