used native PHP 8 functions

Author: dg

src/Forms/Container.php

@@ -488,7 +488,7 @@ public function __call(string $name, array $args)
 
 	public static function extensionMethod(string $name, /*callable*/ $callback): void
 	{
-		if (strpos($name, '::') !== false) { // back compatibility
+		if (str_contains($name, '::')) { // back compatibility
 			[, $name] = explode('::', $name);
 		}
 		self::$extMethods[$name] = $callback;

src/Forms/Controls/BaseControl.php

@@ -556,7 +556,7 @@ public function __call(string $name, array $args)
 
 	public static function extensionMethod(string $name, /*callable*/ $callback): void
 	{
-		if (strpos($name, '::') !== false) { // back compatibility
+		if (str_contains($name, '::')) { // back compatibility
 			[, $name] = explode('::', $name);
 		}
 		self::$extMethods[$name][static::class] = $callback;

src/Forms/Helpers.php

@@ -41,7 +41,7 @@ public static function extractHttpData(
 		$data = Nette\Utils\Arrays::get($data, $name, null);
 		$itype = $type & ~Form::DATA_KEYS;
 
-		if (substr($htmlName, -2) === '[]') {
+		if (str_ends_with($htmlName, '[]')) {
 			if (!is_array($data)) {
 				return [];
 			}