pcbnew, SVG import: fix an issue for SVG files using a CR+LF end of file

The issue was in a validity test working only if CR+LF is not replaced by LF
Fixes #10096
https://gitlab.com/kicad/code/kicad/issues/10096

pcbnew/import_gfx/svg_import_plugin.cpp

@@ -56,8 +56,11 @@ bool SVG_IMPORT_PLUGIN::Load( const wxString& aFileName )
 {
     wxCHECK( m_importer, false );
 
-    // wxFopen takes care of unicode filenames across platforms
-    FILE* fp = wxFopen( aFileName, wxT( "rt" ) );
+    // 1- wxFopen takes care of unicode filenames across platforms
+    // 2 - nanosvg (exactly nsvgParseFromFile) expects a binary file (exactly the CRLF eof must
+    // not be replaced by LF and changes the byte count) in one validity test,
+    // so open it in binary mode.
+    FILE* fp = wxFopen( aFileName, wxT( "rb" ) );
 
     if( fp == nullptr )
         return false;

thirdparty/nanosvg/nanosvg.cpp

@@ -3688,6 +3688,8 @@ NSVGimage* nsvgParseFromFile( FILE *fp, const char* units, float dpi )
     if( data == NULL )
         goto error;
 
+    // This test works only if fp is open in binary mode, i.e. if the CRLF eol is not
+    // replaced by LF when reading the file
     if( fread( data, 1, size, fp ) != size )
         goto error;