Detect when features are deleted in web-features

[jcscottiii]

Our ingestion process should detect when a web feature is deleted (whether it be from an actual deletion or rename).

The process should remove that web feature from the various tables.

In the event of a rename, this process should not try to connect the old identifier's data to the new web feature identifier. (This excludes the case of where the alias field is used and will be addressed in a separate issue)

Without this, the team will need to continually monitor the releases for web-features and see if there are any removals or renames and manually add them to the exclude table.

cc: @foolip