WP-CLI command reference generates duplicate posts

[schlessera]

The cron job that updates the WP-CLI command reference is currently generating massive amounts of duplicate posts.

This issue is due to the fact that CPT slugs share a namespace with other CPTs, and we hit this with commands like embed. The entire synchronization mechanism is built around the URL, and the embed command that has a conflict with _some_ other post on the site is created under the slug embed-2. This causes every check to detect the entry as an existing parent to fail and thus parents are re-created all the time.

I have a patch that normalizes the command path so that these added numeric suffixes are removed from the path that is used for all checks.

[schlessera]

Normalize command paths

[schlessera]

The patch does the following:

• normalize command paths to avoid duplicated items due to slug conflicts
• add 'page-attributes' to CPT 'supports', so that parent posts can be manually inspected/modified
• Only filter the queries for this CPT on the frontend, so that we keep access to all generated commands on the backend

[schlessera]

Fixed a small typo

[danielbachhuber]

In 6545:

devhub/cli: Fix Daniel's broken importer code

Fixes #3421