Fix Summarizer Issue with BelongsToMany Pivot Fields (#19625)

* Allow Summarizer on BelongsToMany pivot columns

* Allow fields that begin with "pivot."

* Fix PHPStan error

* PHPStan fixes

* Add tests

* cleanup and fix edge cases

* Update Summarizer.php

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Co-authored-by: Dan Harrin <git@danharrin.com>

tests/database/migrations/0013_create_department_ticket_table.php

@@ -12,6 +12,8 @@ return new class extends Migration
             $table->id();
             $table->unsignedBigInteger('department_id');
             $table->unsignedBigInteger('ticket_id');
+            $table->unsignedInteger('quantity')->default(1);
+            $table->unsignedInteger('price')->default(0);
             $table->timestamps();
         });
     }