Redesign communicating with the user

[nmaarnio]

EIS CLI uses simple "checkpoint" prints currently. These are useful to inform the user in EIS QGIS Plugin about the progress but are far from ideal. Some improvement ideas listed here:

• In CLI, there could in addition to the percent prints more descriptive prints like "Input data read" etc.
• In CLI, there could be more checkpoint prints
• Some commonly used tools that can take a while to execute (such as distance_computation) could record their progress. This could be enabled with a verbose parameter, or enabled only when CLI calls the tool
• EIS Toolkit could use a proper logging system