Add Bool Service

[pantor]

I often use a service with an additional bool field in my projects, e.g. for motor enabling/disabling, for switching a notification LED or to turn on/off a laser pointer. Any chance that it might be added to the std_srvs package?

[DaikiMaekawa]

👍 I agree your PR because I often add the Bool.srv for our projects.

[dirk-thomas]

We have talked about this and came to the following conclusions:

• In general the generic std_msgs and std_srvs should only be used for prototyping since they don't contain any semantic meaning.
• Considering that the other service is called Trigger this one would be more specifically names with SetBool.
• For semantic meaning a return code should be an integer (not a bool) with return codes defined in the service itself.
• We do see the value of having a SetBool for rapid prototyping though.
• But we won't add additional services like SetInt since those would lack too much semantic on the request data (valid value range, unit, etc.).

That being said I have cherry-picked a modified version of this with the service name being called SetBool in 688af91

Thanks.