Introduce KaraboLogger

[Lukas113]

We have a lot of print statements in Karabo. However, this is not very flexible and easy to use. The following are just a set of use-cases to show how limited print-statements are:

• Control verbosity levels (e.g. lvl 1-3)
• Not have to check verbose each time before a print
• Control prints in case of parallel processes (e.g. print messages only on main-device or on each device)
• Set output stream (stderr, stdout) & handler for print & warnings
• Beeing able to control local and global verbosity (e.g. suppress temporary karabo-prints using the with-statement)

These is just an illustration how Karabo could benefit from a logger. And implementing a logger with basic functionality (just replacing the pring-statements with a console-logger) without having to care about specific use-cases should be easy and fast to implement.