text: Title: Enhance PCA Decomposition
  Body: We should enhance the `PCADecomposition` visualizer to provide many of the features the `Manifold` visualizer provides, including things like:
  
  - [ ] Color points by class with a legend (See #458)
  - [ ] Color points by heatmap for continuous y and add a colorbar 
  - [ ] Add alpha parameter (see #475)
  - [ ] Add random state to pass to PCA 
  - [ ] Allow user to pass in a PCA transformer/pipeline 
  - [ ] Update tests with better random data sets (more points; see manifold tests) 
  - [ ] Include explained variance/noise variance (or explained variance ratio) in chart  
  - [ ] Enhance biplots documentation
  
  See also #455 as another enhancement that might not be related to this enhancement. 