feat(Provider): Rendering performance telemetry

[miroslavstastny]

Add rendering performance telemetry to understand how much time the application spends rendering Stardust components.

How to use

Add telemetryRef prop to the Provider:

const telemetryRef = React.useRef<Telemetry>()

return (
  <Provider telemetryRef={telemetryRef}>
  ...
  </Provider>
)

Stardust immediately starts measuring performance of all components inside that Provider (including nested Providers).

To enable/disable the telemetry, set enabled property:

telemetryRef.current.enabled = false

To reset the data gathered so far, call reset():

telemetryRef.current.reset()

Gathered data are available in performance:

const totals = _.reduce(telemetry.current.performance, (acc, next) => {
    acc.count += next.count
    acc.msTotal += next.msTotal
    return acc
  },
  { count: 0, msTotal: 0 },
)

console.log(`Rendered ${totals.count} Stardust components in ${totals.msTotal} ms`)
console.table(telemetry.performance)

Example output:

Implementation

Most of the rendering time is spent inside renderComponent function.
This PR adds markers to that function to measure the time spent inside that per-component name.

[levithomason]

Let move the telemetry counting to the Telemetry class per discussion. Also, add an msAvg getter for ease of use.

[miroslavstastny]

Let move the telemetry counting to the Telemetry class per discussion. Also, add an msAvg getter for ease of use.

Discussed offline, we'll do this later. Let's get the first version rollin'.