Spectra and Hyperspectra size and aspect ratio

[borondics]

To be able to consistently produce spectral outputs we will need a feature that allows to set the size and the aspect ratio of the graph.

I imagine that this would be two text boxes below each other that allows a float and an int inputs and the result would be that the aspect ratio will be changed to 1:<input_float> and the size to <input_int>:<input_int*input_float>. Then the user could also freely resize the window with this aspect ratio and/or turn off the fixed aspect ratio feature for free resizing.