[bin] Fix all the scripts that had errors

[cbentejac]

Description

This PR fixes errors on different Meshroom scripts that thus could not be run, or crashed when some specific arguments were set. More specifically, it targets:

• meshroom_submit:
  • The input argument containing the path of the project file to submit was never used to call the core.graph's "submit" method;
  • Instead, two invalid arguments were used;
• meshroom_status: The --toNode option caused errors when retrieving the list of nodes up to toNode;
• meshroom_statistics:
  • The script was still performing Python 2-imports;
  • It relied on a method in the core.stats module that was broken: when reading the statistics file, the computer and process statistics where initialized to empty dictionaries instead of ComputerStatistics and ProcStatistics objects, meaning the file was read but its content was never stored;
  • It used an outdated version of the Matplotlib API.

Features list

• Properly initialize the ComputerStatistics and ProcStatistics objects when reading a statistics file;
• Fix all the errors when running meshroom_submit, meshroom_status and meshroom_statistics.