Plot 2D or 3D PCA for multiOmicDataset
See also
plot_pca() generic
Other plotters for multiOmicDataSets:
plot_corr_heatmap,MOSuite::multiOmicDataSet-method,
plot_histogram,MOSuite::multiOmicDataSet-method,
plot_read_depth,MOSuite::multiOmicDataSet-method
