Documentation - Fix whitespaces (#809)

- Corrected spelling errors in comments (e.g., "od" to "of", "thr" to "the")
- Removed unnecessary `<br>` HTML tags from comment formatting
- Normalized whitespace in comments for consistency
- Fixed terminology (e.g., "3-d" to "3D")

src/Visualization/TKService/Graphic3d/Graphic3d_Structure.hxx

@@ -315,7 +315,7 @@ public:
   Standard_EXPORT void Ancestors(Graphic3d_MapOfStructure& SG) const;
 
   //! If Atype is TOC_DESCENDANT then add <AStructure>
-  //! as a child structure of  <me>.
+  //! as a child structure of <me>.
   //! If Atype is TOC_ANCESTOR then add <AStructure>
   //! as a parent structure of <me>.
   //! The connection propagates Display, Highlight, Erase,

src/Visualization/TKService/Graphic3d/Graphic3d_Texture2Dplane.hxx

@@ -58,8 +58,8 @@ public:
 
   //! Defines the texture projection plane for both S and T texture coordinate
   //! default is NOTP_XY meaning:
-  //! <1.0, 0.0, 0.0, 0.0> for S
-  //! and  <0.0, 1.0, 0.0, 0.0> for T
+  //! <1.0, 0.0, 0.0, 0.0> for S and
+  //! <0.0, 1.0, 0.0, 0.0> for T
   Standard_EXPORT void SetPlane(const Graphic3d_NameOfTexturePlane thePlane);
 
   //! Defines the texture scale for the S texture coordinate
@@ -103,13 +103,13 @@ public:
                               Standard_ShortReal& C,
                               Standard_ShortReal& D) const;
 
-  //! Returns   the current texture plane T equation
+  //! Returns the current texture plane T equation
   Standard_EXPORT void PlaneT(Standard_ShortReal& A,
                               Standard_ShortReal& B,
                               Standard_ShortReal& C,
                               Standard_ShortReal& D) const;
 
-  //! Returns  the current texture S translation value
+  //! Returns the current texture S translation value
   Standard_EXPORT void TranslateS(Standard_ShortReal& theVal) const;
 
   //! Returns the current texture T translation value

src/Visualization/TKService/Graphic3d/Graphic3d_TypeOfAnswer.hxx

@@ -18,7 +18,7 @@
 #define _Graphic3d_TypeOfAnswer_HeaderFile
 
 //! The answer of the method AcceptDisplay
-//! AcceptDisplay  means is it possible to display the
+//! AcceptDisplay means is it possible to display the
 //! specified structure in the specified view ?
 //! TOA_YES yes
 //! TOA_NO  no