Transfer adjust call to applyposition

This transfers the responsibility of the adjust() call to
applyposition().

This is because cutscene text boxes (TEXTTRANSLATE_CUTSCENE) will have
adjust() called, but all other text boxes won't. And I can't place the
adjust() call inside applyposition(), because adjust() also calls
applyposition(), and that leads to an infinite loop which leads to a
stack overflow, so I had to remove the applyposition() call from
adjust(), and replace the other existing call to
Graphics::textboxadjust() with Graphics::textboxapplyposition(), and
then remove Graphics::textboxadjust() function because it's no longer
used.

desktop_version/src/Graphics.h

@@ -127,8 +127,6 @@ public:
 
     void textboxapplyposition(void);
 
-    void textboxadjust(void);
-
     void addline(const std::string& t);
 
     void setlarge(bool large);