[Core][Logger] Add option to output a time stamp at the beginning of each log line

[armingeiser]

Similar to the severity level, a flag for adding the time stamp at the beginning of each log line can be set to the Logger.

[time stamp] - [label]: [message]

e.g.

11:26:52 - ShapeOpt: Current value of objective =   1.11393E-07 

This can be activated by:

KM.Logger.GetDefaultOutput().SetTimeStampFlag(True)

@KratosMultiphysics/technical-committee

[loumalouomega]

I do not agree, why not using the timer that already exist in kratos?

[loumalouomega]

Some comments

[armingeiser]

I do not agree, why not using the timer that already exist in kratos?
@loumalouomega do you mean putting the function to get the time stamp into the timer.h?

[loumalouomega]

I do not agree, why not using the timer that already exist in kratos?
@loumalouomega do you mean putting the function to get the time stamp into the timer.h?

I said that before check the code, sorry I thought this was a timer 2.0, nevermind

[pooyan-dadvand]

I like the feature and think that it is really useful. However, I have some comments about how it is done:

1. Please note that the message has a mTime member which I would initialize it in the constructor of the message. So we would get the same timestamp for the same message in all outputs.
2. I would make the LoggerOutput in charge of timestamp formatting. This make it customizable f like other output formatting and not fixed by the unique message class.
3. Personally I like more a dense YYYYMMDDHHmmss format which is normally used in log files. Of course, this is my personal opinion and I am open to hear others on it.