Make Pepper stop listening to itself

User Story/Description

As a Pepper robot I don't want to listen to myself to keep myself from a monologue

Definition of Done

A node or existing node implements an estimate of how long it takes for Pepper to say anything and then sends a flag in ROS that the robot is currently speaking (e.g. through a latched topic)

How

Probably in the animated_speech node or similar. Need to take the speed of pepper's TTS in the estimate. E.g. sometimes its on 100% aor 60%, it will affect the estimation.

Set different speeds and measure the time it takes to get some sort of formula for "how long does it take to say x words with the speed in account".