[TASK] Move content of "Data Types"

There are no real data types in TypoScript, there are just certain
string formats expected in some properties.

Where the former "data type" is an expected input for exactly one function, move the expected input to that function.

Where it works like a function itself, move it to functions,

Move the rest of expected string formats to the syntax but make clear they are no real types.

Releases: main, 13.4

Documentation/ContentObjects/Hmenu/Tmenu/Index.rst

@@ -40,7 +40,7 @@ These properties are all the item states used by :typoscript:`TMENU`.
 ..  warning::
 
     Be aware to properly escape menu item content in order to prevent
-    Cross-site scripting vulnerabilities. It is therefore highly recommended 
+    Cross-site scripting vulnerabilities. It is therefore highly recommended
     to use :php:`stdWrap.htmlSpecialChars = 1` in all TMENU item states.
 
 The following Item states are listed from the least to the highest priority:
@@ -287,7 +287,7 @@ Properties
 
     ..  confval:: target
         :name: menu-common-properties-target
-        :type: :ref:`data-type-target`
+        :type: string
         :Default: self
 
         Target of the menu links

Documentation/ContentObjects/Hmenu/Tmenu/Tmenuitem.rst

@@ -193,7 +193,7 @@ Properties
 
 ..  confval:: altTarget
     :name: tmenuitem-altTarget
-    :type: :ref:`data-type-target`
+    :type: string
 
     Alternative target overriding the target property of the
     ref:`TMENU <tmenu>`, if set.