Block Bindings: Show attributes panel in custom post types

[santosguillamot]

The attributes panel isn't shown while editing custom post types when Gutenberg is not installed. This is caused because each post type can define a capability_type, which by default posts, so the logic to map the capabilities wasn't correct, and it was returning false.

While working on the compatibility filter of the mapping capabilities introduced ​here, I've realized that there is a bug where the attributes panel is not shown in custom post types. This is caused because each post type can define a capability_type, which by default is post, so the logic to map the capabilities wasn't correct and it was returning false.

This bug wasn't triggered by Gutenberg e2e tests because the old compat filter was overriding the setting introduced in core. This should be solved with ​this change.

Trac ticket: https://core.trac.wordpress.org/ticket/62226

[cbravobernal]

In 59239:

Block Bindings: Fix panel not appearing in custom post types.

There is a bug where the attributes panel is not shown in custom post types. This is caused because each post type can define a capability_type, which by default is post, so the logic to map the capabilities wasn't correct and it was returning false.

Props santosguillamot, cbravobernal.
Fixes #62226.

Committed with https://core.trac.wordpress.org/changeset/59239