Improve validation error wording

Resolves #9960

Author: brandonkelly

CHANGELOG-WIP.md

@@ -2,6 +2,7 @@
 
 ### Administration
 - Assets and Categries fields no longer have “Show the site menu” settings. ([#17156](https://github.com/craftcms/cms/issues/17156))  
+- Improved the wording of validation errors caused by relational fields’ “Validate related [type]” settings. ([#9960](https://github.com/craftcms/cms/discussions/9960))  
 
 ### Extensibility
 - Added `craft\fields\BaseRelationField::canShowSiteMenu()`.

src/fields/BaseRelationField.php

@@ -537,10 +537,13 @@ public function validateRelatedElements(ElementInterface $element): void
         }
 
         if ($errorCount) {
-            $elementType = static::elementType();
-            $element->addError($this->handle, Craft::t('app', 'Validation errors found in {attribute} {type}; please fix them.', [
-                'type' => $errorCount === 1 ? $elementType::lowerDisplayName() : $elementType::pluralLowerDisplayName(),
-                'attribute' => Craft::t('site', $this->name),
+            $selectedCount = (int)$value->count();
+            $element->addError($this->handle, Craft::t('app', 'The selected {relatedType} {count, plural, =1{contains} other{contain}} validation errors, preventing this {type} from being saved. Edit the {relatedType} to fix them.', [
+                'relatedType' => $selectedCount === 1
+                    ? static::elementType()::lowerDisplayName()
+                    : static::elementType()::pluralLowerDisplayName(),
+                'count' => $selectedCount,
+                'type' => $element::lowerDisplayName(),
             ]));
         }
     }

src/translations/en/app.php

@@ -1514,6 +1514,7 @@
     'The primary site will be loaded by default on the front end.' => 'The primary site will be loaded by default on the front end.',
     'The request could not be understood by the server due to malformed syntax.' => 'The request could not be understood by the server due to malformed syntax.',
     'The requested URL was not found on this server.' => 'The requested URL was not found on this server.',
+    'The selected {relatedType} {count, plural, =1{contains} other{contain}} validation errors, preventing this {type} from being saved. Edit the {relatedType} to fix them.' => 'The selected {relatedType} {count, plural, =1{contains} other{contain}} validation errors, preventing this {type} from being saved. Edit the {relatedType} to fix them.',
     'The server doesn’t meet Craft’s new requirements:' => 'The server doesn’t meet Craft’s new requirements:',
     'The table name prefix' => 'The table name prefix',
     'The template Craft CMS will use for HTML emails' => 'The template Craft CMS will use for HTML emails',
@@ -1728,7 +1729,6 @@
     'Validate custom fields on public registration' => 'Validate custom fields on public registration',
     'Validate related {type}' => 'Validate related {type}',
     'Validation errors for site: “{siteName}“' => 'Validation errors for site: “{siteName}“',
-    'Validation errors found in {attribute} {type}; please fix them.' => 'Validation errors found in {attribute} {type}; please fix them.',
     'Value prefixed by “{prefix}”.' => 'Value prefixed by “{prefix}”.',
     'Value suffixed by “{suffix}”.' => 'Value suffixed by “{suffix}”.',
     'Value' => 'Value',