Fix channel, rates and extended rates

[Fufuches]

• Delete the "chardet" import because it wasn't used.
• Modify the way to take channel to avoid potential parsing issues.
• Print the rates and extended rates in Mbit/sec.
• Change the way to take the Extended rates because initially it is just the rates in another format.
• Delete one vendor from the hash because there were two.
• Change the airbase-ng hash because of the modifications.