Unify the 3 dynamic reconfigure servers into one (retaining tabs)

[corot]

Hi, this issue is both a question and a proposal.

question:
what are the benefits of splitting the dynamic reconfigurable parameters into 3 servers? The drawback I found is that we cannot treat MPC as any other local planner when changing generic parameters as the goal tolerances.

proposal:
replicate TEB architecture with a single server but multiple tabs, so parameters are neatly distributed on RQT reconfigure but still accessible under a predictably named server (we will PR the change if deemed opportune).

[kosmastsk]

This change was introduced in #24 . The initial implementation contained only a single .cfg file for all dynamic reconfigure parameters.

[corot]

I see the problem; but seems to me that PR #24 is adapting to the parameters namespace structure created with this example configuration

I think it would had been simpler to rewrite the configuration file declaring all MPC parameters in its own file and all the other parameters in a separated testing configuration. The 3 reconfigure servers looks rather overkilling to me