Support file parsing

[Kiyotoko]

Is your feature request related to a problem? Please describe.
Currently, scvis can only parse terminal input. For creating modules and larger projects, file parsing is required.

Describe the solution you'd like
In addition to creating a scanner to the default input stream, add a possibility to also read the content of a file over file input stream and parse all lines after another.

Describe alternatives you've considered
This is required and therefore has no alternatives.