Update API documentation for Goals (#24363)

* Updated API documentation for Goals plugin

* Keep existing class level docs

* Fixed idSite inconsistency

* Update API documentation for Goals

* apply further improvements

---------

Co-authored-by: Lachlan Reynolds <lachlan.reynolds@innocraft.com>

Author: sgiehl

core/Site.php

@@ -53,7 +53,7 @@ class Site
     ];
 
     /**
-     * @var int|null
+     * @var int
      */
     protected $id = null;
 

phpstan-baseline.neon

@@ -3328,11 +3328,6 @@ parameters:
 			count: 1
 			path: plugins/Goals/API.php
 
-		-
-			message: "#^Parameter \\#6 \\$columns of method Piwik\\\\Plugins\\\\Goals\\\\API\\:\\:get\\(\\) expects array, string given\\.$#"
-			count: 1
-			path: plugins/Goals/API.php
-
 		-
 			message: "#^Variable \\$table in isset\\(\\) always exists and is not nullable\\.$#"
 			count: 1
@@ -3398,11 +3393,6 @@ parameters:
 			count: 1
 			path: plugins/Goals/Pages.php
 
-		-
-			message: "#^Parameter \\#1 \\$idSite of method Piwik\\\\Plugins\\\\Goals\\\\API\\:\\:getGoals\\(\\) expects array\\|string, int\\|null given\\.$#"
-			count: 1
-			path: plugins/Goals/RecordBuilders/GeneralGoalsRecords.php
-
 		-
 			message: "#^Strict comparison using \\=\\=\\= between array\\|Zend_Db_Statement and false will always evaluate to false\\.$#"
 			count: 1