ECA UI module in Drupal CMS distribution does not expose list of available events ([entity_type], [operation])

Problem/Motivation

When using the Drupal CMS distribution (not just Drupal Core), the ECA UI module does not display the expected "Available Events" section or the "List all available events" button under /admin/config/workflow/eca/settings. This limits the ability of site builders to discover available [entity_type], [operation] combinations such as webform_submission.load.draft, node.insert, etc., which are essential for configuring BPMN-based ECA models.

This functionality appears normally when ECA + ECA UI are used on standard Drupal Core installations but is either hidden, overridden, or disabled in the Drupal CMS distribution.

Steps to reproduce

3. Steps to Reproduce
Install Drupal CMS (distribution version, not plain Core).
Enable ECA and ECA UI modules.
Navigate to /admin/config/workflow/eca.
Click on the Settings tab.
Scroll to the bottom — the "Available Events" section or a "List all available events" interface is missing.
Compare with a fresh install of Drupal Core + ECA + ECA UI, where the list appears normally.

Proposed resolution

Ensure that the "Available Events" section in ECA UI is not being overridden or hidden by the Drupal CMS distribution. If a permissions or UI override is at fault, resolve the conflict so that ECA UI behaves as expected. Alternatively, provide a fallback mechanism (e.g., route access or a permissions check) so users can still access the list of available events regardless of the Drupal flavor.

Remaining tasks

Reproduce the issue on the latest Drupal CMS distribution.
Test the ECA + ECA UI combination on plain Drupal Core to confirm expected behavior.
Identify which module or configuration in Drupal CMS might be suppressing the "Available Events" UI.
Patch or document the workaround or fix.
Optionally: expose the event discovery route via a permissions update or config override.

User interface changes

Restore or expose the missing section:
The Available Events list at /admin/config/workflow/eca/settings
A searchable UI for listing event machine names (like node.insert, webform_submission.load.draft, etc.)

The actual eca_webform module does not define the expected: webform_submission.insert, webform_submission.update, or webform_submission.state events.

Instead, it dispatches custom-named ECA events, such as:
-webform:submission_access
-webform:submission_query_access_alter
-webform:submissions_pre_purge
-webform:submissions_post_purge

API changes

No API changes expected. The issue pertains to administrative UI exposure of already-registered ECA events.

Data model changes

None.