[Proposal] Improve and expand visualization type definitions for easier plugin use

[joshuarrrr]

There are many features where a plugin author might need to provide a pre-configured visualization in their application. For consistent look, feel, and interaction experience, we'd like to make it as easy as possible to embed one of the visualization types already defined in OpenSearch Dashboards. For example, if a security analytics plugin wanted to provide a histogram on the homepage of their app, they could simply get a react component from the visualization type:

import { ReactHistogram } from './vislib`

const histogramData = /* some data source */

...

return (
  <ReactHistogram data={data} />
);

We currently have a number of visualization types implemented, with fairly powerful configuration options. However, to use them effectively requires deep understanding of core dashboards concepts, because a developer needs to understand how to properly specify and format visualization configurations (not generally documented), and how to use the expressions plugin to properly format and pass data. They may also need understanding of how the visualizations plugin provides an embeddable, and how to integrate that properly into an app page.

Potential tasks:

• Audit and improve default visualization configurations
• Add high-level React components to existing VisLib types
  • Line chart
  • Area chart
  • Histogram
  • Horizontal bar chart
  • Heatmap
  • Pie chart
  • Gauge
  • Goal