[Feature Anywhere] Add a generic interface for overlaying data on a Visualization

[ohltyler]

There are many ways we may want to support adding to and/or augmenting the source visualization data to provide additional insights. We can introduce a generic VisLayer interface that can be extended, to define a variety of ways we can layer data onto a visualization. We list out a few below:

1. Point-in-time-event layering (PointInTimeEventsVisLayer). This layer can be used when we want to show a set of particular events occurring, such as anomalies or alerts.
2. Time-series layering (TimeSeriesVisLayer). This can be used to add an additional time series onto a visualization, possibly even changing the global time range for the visualization. An example of when this layer may be used is using forecasting to project forecasted data points in the future.

[ohltyler]

Closing via #3108