Improvements for the map_annotation_tool

[argenos]

In addition, I have a few minor issues/suggestions:

1. Currently, the tool looks for the mcr_default_env_config package and writes it to the map specified in ROBOT_ENV. athome doesn't save the maps there, and using the environment variable becomes a bit problematic to configure when annotating different maps.
   Possible solution:
   • configure this from within rviz (once the plugin has been launched)
   • explore the use of parameters or topics
2. Writing the poses directly on the robot
   Possible solutions:
   • Doing this via topics with a node

Part of this issue was originally found in b-it-bots/map_annotation_tool#2

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.