Fixes for PHP 8.2 in tcpdf_fonts.php - fixes #632 (#633)

* Update tcpdf_fonts.php

Fixes "use of "self" in callables is deprecated" warning is arising from tcpdf_fonts.php when using PHP >= 8.2

* Update tcpdf_fonts.php for PHP 5.3-8.2 compatibility

PHP 8.2 "use of "self" in callables is deprecated" yet some ways of fixing this breaks for PHP 5.3. This approach works, tested PHP 5.3.29 - 8.2.0

* Update tcpdf_fonts.php

Spaces added back in before arguments

* Update tcpdf_fonts.php using get_called_class()

Maneuvers compatibility of callables inside array_map() between PHP 5.3 and 8.2 - tested.

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Co-authored-by: Nicola Asuni <nicolaasuni@users.noreply.github.com>

include/tcpdf_fonts.php

@@ -1780,9 +1780,9 @@ public static function arrUTF8ToUTF16BE($unicode, $setbom=false) {
 	 */
 	public static function UTF8ArrayToUniArray($ta, $isunicode=true) {
 		if ($isunicode) {
-			return array_map(array('TCPDF_FONTS', 'unichrUnicode'), $ta);
+			return array_map(get_called_class().'::unichrUnicode', $ta);
 		}
-		return array_map(array('TCPDF_FONTS', 'unichrASCII'), $ta);
+		return array_map(get_called_class().'::unichrASCII', $ta);
 	}
 
 	/**
@@ -2002,7 +2002,7 @@ public static function UTF8StringToArray($str, $isunicode, &$currentfont) {
 		if ($isunicode) {
 			// requires PCRE unicode support turned on
 			$chars = TCPDF_STATIC::pregSplit('//','u', $str, -1, PREG_SPLIT_NO_EMPTY);
-			$carr = array_map(array('TCPDF_FONTS', 'uniord'), $chars);
+			$carr = array_map(get_called_class().'::uniord', $chars);
 		} else {
 			$chars = str_split($str);
 			$carr = array_map('ord', $chars);