Bookoo features

[same31]

Adds two BOOKOO scales specific commands in the main library:

• tareStartTimer(): Allows to tare, reset and start the timer in a single command, as recommended by Bookoo docs.
• beep(int level): Sets the beep level of the scale, useful to simply make the scale feedback a beep without triggering a tare

Added some configuration variables:

• bool tareStartTimer (default false): to do the trio of commands in one go)
• bool beep (default false): To beep instead of performing a tare, also will inform the user at the end of the shot once final weight offset has been confirmed / written
• uint8_t beepLevel (default 0): To set the beep level from 0 (silent) to 5 (loudest)