[slapos.collect] Refactor and Collect information from Computer and System

Major changes
  Rename pymonitor, add dependency and simplify
  Save all information using sqllite
  Record information from all processes individually
  Implement Snapshot for Computer and Systems information
  General Clean up
[slapos.grid] Place instance logs on instance side.
[slapos.cli.register] Update comment.
[slapos.core] Remove cli_legacy