Fix debugPlots in SurveySimulation prototype

[dsavransky]

Describe the bug
Currently, make_debug_bird_plots requires loading code from tools folder, which is not packaged with EXOSIMS and which will not work unless running from EXOSIMS root.

Steps to fix:

1. Move obs_plot from tools into util. Add whatever decorator/magic to make matplotlib an optional dependency. Do not add matplotlib to actual package reqs.
2. Update obs_plot to fail gracefully if no matplotlib
3. Update SurveySimulation prototype to point to the right version of obs_plot
4. Conslidate debug_plot_path and make_debug_bird_plots into single keyword
5. Add all associated keywords to _outspec