[Backport 13.4] [BUGFIX] Do not pretend to be a cObject (#1515)

* [BUGFIX] Do not pretend to be a cObject

`templateName` is of type string/stdWrap.
However, the snippet gives the impression that it is a cObject due to `templateName = TEXT`.

Working:
```
templateName = Default
```

Working
```
templateName.stdWrap.cObject = TEXT
templateName.stdWrap.cObject.value = Default
```

*Not* working
```
templateName= TEXT
templateName.value = Default
```

* [TASK] Remove unnecessary stdWrap

No extra `stdWrap` is necessary. `templateName` has direct stdWrap behaviour.

Related: #1513

---------

Co-authored-by: Julian Hofmann <[email protected]>
Co-authored-by: Julian Hofmann <[email protected]>

Documentation/ContentObjects/Fluidtemplate/_includes/_templateNameAutomatic.typoscript

@@ -1,7 +1,6 @@
 lib.stdContent = FLUIDTEMPLATE
 lib.stdContent {
-    templateName = TEXT
-    templateName.stdWrap {
+    templateName {
         cObject = TEXT
         cObject {
             data = levelfield:-2,backend_layout_next_level,slide