PCH: include excerpt generator in Content Helper sidebar panel

[danielabloch]

Is your feature request related to a problem?

When using the Parse.ly Content Helper, customers are not aware that we offer smart excerpt generation (powered by their performance data + our ML system/AI). This means one of the capabilities we built is unknown and thereby unused by customers.

Describe the solution you'd like

Include the existing excerpt generation feature in the Parse.ly Content Helper panel in Block Editor interface

Excerpt generator in main Post tab for WordPress settings

Where it should be also added > Content Helper tools tab

Its placement should be below Title Suggestions and above Smart Linking because that is its logical placement within the publishing workflow

Describe alternatives you've considered

N/A

Additional context

After discussing it, we see no harm in offering the feature in both the WP settings tab and PCH tab so please keep it in the former and add it to the latter