With this commit, the WireGuard component exits with a descriptive uncaught
exception on invalid configurations or when the user attempts to re-configure
attributes that are not re-configurable (private_key, listen_port, interface).
This is particularly important when it comes to the not re-configurable private
key. If the component would just ignore the attempt to override the private
key, the user may come to believe that his old (potentially compromised)
private key is not in use anymore.
The fact that the component now exits instead shouldn't be a problem, as the
user would have to restart the component anyway in order to apply the new
attribute values.
The commit also extends the wg_reconfig run script to test that WireGuard
exits on the attempt to re-configure the private key.
Ref #4520
Support removing peers by removing them from the component configuration.
This commit also introduces the wg_reconfig run script that tests adding and
removing single peers.
Ref #4520
