Add utility function to generate a set of transforms for a sample

[whitews]

Given a Sample instance, generate a set of transforms for every channel. The set would create linear transforms for scatter & time channels and logicle transforms for fluorescence channels. The appropriate transform parameters (e.g. 'param_t') for each channel would be determined by the Sample metadata. The function would live in sample_utils and return a dictionary where key was the channel PnN label and the value was a Transform instance.