fix(chore): replace jquery trim with vanilla js

Replaces the used jquery trim methods by its native vanilla javascript variant. As of jquery 3.5.0 the trim method gets deprecated

Author: lubber-de

src/definitions/behaviors/form.js

@@ -336,7 +336,7 @@ $.fn.form = function(parameters) {
             }
           },
           blank: function($field) {
-            return $.trim($field.val()) === '';
+            return String($field.val()).trim() === '';
           },
           valid: function(field) {
             var
@@ -1264,7 +1264,7 @@ $.fn.form = function(parameters) {
                 // cast to string avoiding encoding special values
                 value = (value === undefined || value === '' || value === null)
                     ? ''
-                    : (settings.shouldTrim) ? $.trim(value + '') : String(value + '')
+                    : (settings.shouldTrim) ? String(value + '').trim() : String(value + '')
                 ;
                 return ruleFunction.call(field, value, ancillary, $module);
               }

src/definitions/modules/dropdown.js

@@ -1773,7 +1773,7 @@ $.fn.dropdown = function(parameters) {
             return $text.text();
           },
           query: function() {
-            return $.trim($search.val());
+            return String($search.val()).trim();
           },
           searchWidth: function(value) {
             value = (value !== undefined)
@@ -1916,8 +1916,8 @@ $.fn.dropdown = function(parameters) {
               return ($choice.data(metadata.text) !== undefined)
                 ? $choice.data(metadata.text)
                 : (preserveHTML)
-                  ? $.trim($choice.html())
-                  : $.trim($choice.text())
+                  ? $choice.html().trim()
+                  : $choice.text().trim()
               ;
             }
           },
@@ -1929,11 +1929,11 @@ $.fn.dropdown = function(parameters) {
             return ($choice.data(metadata.value) !== undefined)
               ? String( $choice.data(metadata.value) )
               : (typeof choiceText === 'string')
-                ? $.trim(
+                ? String(
                   settings.ignoreSearchCase
                   ? choiceText.toLowerCase()
                   : choiceText
-                )
+                ).trim()
                 : String(choiceText)
             ;
           },