fix(float-window-manager): sway version compare

[sakarie9]

String compare will cause issues like "1.10.1 is smaller than 1.6".

This version of Sway is earlier than supports moving windows with percentages.
Version is '1.10.1'. Version needed: '1.6'.

We can use sort -V instead.

[scott092707]

I just added (to mine) a notify-send for this, as if it doesn't start, the user ought to know why without needing to look at the log:
notify-send "Float Window Manager: Sway version '$min_version' or higher required."
and modified the notify-send for the commands to:
notify-send "Float Window Manager: Not all required commands found."
for consistency in messages (matches "...starting Float Window Manager...")

[scott092707]

[Wasn't sure how to do this officially, as your change has not yet reached the official code...]