Verified mel spectrograms in winml sample against pytorch

[janezdu]

Main changes included in this PR involve:

• Tuned the mel spectrogram settings to match more closely with PyTorch. Rendering the tensor data from a learning model in python/librosa shows that the learning model creates a mel spectrogram very similar to the ones made by torchaudio.
• UI controls for the settings of the melspectrogram added
• Resampling via learning model added
• Some refactoring in PreprocessModel.cs; methods are now "less static" and include information about the audio file/mel spectrogram settings stored as instance properties.
• Flip and transpose mel spectrogram in learning model so that time axis goes left to right and Mel matrix goes low to high (up to down)