Use SetParameter Launch API to set the yaml filename for map_server

[SteveMacenski]

Would let us remove the RewrittenYaml remappings entirely and let us remove the requirement of a bogus yaml_filename entry in the yaml file to be overwritten. Now, it could just not be present at all and that would be fine. Just need to make sure that this is set only for the map_server node, which should be straight forward.

See #3131 for a motivating example and fixes #3111 to be less quirky @superseppl. Thanks @tonynajjar once again for a timely PR that helps fix another problem

Note that we should also remove the note I added to the navigation.ros.org configuration for map server explaining that yaml_filename is strictly required.

[stevedanomodolor]

@SteveMacenski I can try it this weekend

[SteveMacenski]

Awesome!