(REF) dev/core#1744 - Simplify Afform event naming

[ahed-compucorp]

Overview

This PR replaces the last usage of constants for event names in CiviCRM code base with string literal.

Before

The ext/afform/core/afform.php file uses constants for event names.

-  Civi::dispatcher()->addListener(Submit::EVENT_NAME, [Submit::class, 'processContacts'], 500);                                                                         
-  Civi::dispatcher()->addListener(Submit::EVENT_NAME, [Submit::class, 'processGenericEntity'], -1000);                                                                  

After

The ext/afform/core/afform.php file uses string literal for event names.

+  Civi::dispatcher()->addListener('civi.afform.submit', ['\Civi\Api4\Action\Afform\Submit', 'processContacts'], 500);                                                   
+  Civi::dispatcher()->addListener('civi.afform.submit', ['\Civi\Api4\Action\Afform\Submit', 'processGenericEntity'], -1000);  

Technical Details

Since CiviCRM 5.26, the convention was to use string literal for event names and the usage of constants was deprecated according to this issue dev/core#1744. This was the last usage of constants for event names in CiviCRM code base.

Comment

Also, it addresses the failing deployments for two of our sites with afform extension enabled after deploying them on another server e.g. creating dev/staging sites.

I've seen the following error on two sites that had afform extension enabled recently:

$ drush cc all
Error: Class "Civi\Api4\Action\Afform\Submit" not found in afform_civicrm_config() (line 52 of civicrm/ext/afform/core/afform.php).
Drush command terminated abnormally due to an unrecoverable error

[civibot]

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[colemanw]

Looks good to me.