encoding.html: add escape() function (#16666)

vlib/vweb/vweb.v

@@ -10,6 +10,7 @@ import net.http
 import net.urllib
 import time
 import json
+import encoding.html
 
 // A type which don't get filtered inside templates
 pub type RawHtml = string
@@ -725,12 +726,5 @@ fn send_string(mut conn net.TcpConn, s string) ! {
 // It used by `vlib/v/gen/c/str_intp.v:130` for string interpolation inside vweb templates
 // TODO: move it to template render
 fn filter(s string) string {
-	return s.replace_each([
-		'<',
-		'&lt;',
-		'"',
-		'&quot;',
-		'&',
-		'&amp;',
-	])
+	return html.escape(s)
 }