Align Jetpack premium block upgrade nudge event with other Calypso upgrade nudges

Having different names and props makes it hard to compare how CTAs perform against each other.

We should have the same event name with other CTAs in Calypso and we'll segment by property.

In Jetpack currently:
https://github.com/Automattic/jetpack/blob/03212a4ae7fe3fe060c231d00702d1b7eecf8dd1/extensions/shared/components/upgrade-nudge/index.jsx#L95-L98

In Calypso they look more like:
```js
recordTracks( 'calypso_upgrade_nudge_cta_click', {
cta_name: event,
cta_feature: feature,
cta_size: 'regular',
} );
```

See p9Jlb4-17c-p2/#comment-1798

Start in extensions/shared/components/upgrade-nudge/index.jsx at the referenced event-tracking code, then compare it with the Calypso upgrade-nudge example in the issue. Done means the Jetpack premium block upgrade nudge uses the shared event name and the cta_name, cta_feature, and cta_size properties described there.

Written by the indexing model from the issue text.