Upgrade from Smarty 3 to Smarty 4 to be PHP 8.1 compatible

Remove all Smarty4 dedicated tests, all are done in the same test file
like before

www/lib/smarty-4.1.0/docs/designers/language-combining-modifiers.md

@@ -0,0 +1,35 @@
+Combining Modifiers {#language.combining.modifiers}
+===================
+
+You can apply any number of modifiers to a variable. They will be
+applied in the order they are combined, from left to right. They must be
+separated with a `|` (pipe) character.
+
+
+    <?php
+
+    $smarty->assign('articleTitle', 'Smokers are Productive, but Death Cuts Efficiency.');
+
+    ?>
+
+where template is:
+
+
+    {$articleTitle}
+    {$articleTitle|upper|spacify}
+    {$articleTitle|lower|spacify|truncate}
+    {$articleTitle|lower|truncate:30|spacify}
+    {$articleTitle|lower|spacify|truncate:30:". . ."}
+
+      
+
+The above example will output:
+
+
+    Smokers are Productive, but Death Cuts Efficiency.
+    S M O K E R S   A R ....snip....  H   C U T S   E F F I C I E N C Y .
+    s m o k e r s   a r ....snip....  b u t   d e a t h   c u t s...
+    s m o k e r s   a r e   p r o d u c t i v e ,   b u t . . .
+    s m o k e r s   a r e   p. . .
+
+