Updating comments per the C++ core guidelines and removing trailing whitespace (#194)

Fixed comments that were inconsistent with the style guidelines described in C++ core guidelines and the modern C++/WinRT language projections and removed trailing whitespace.

Inserted a space after the beginning of the comment so the text wasn't touching the // on all occurrences.

Removed all occurrences of trailing whitespace

src/Calculator/Views/UnitConverter.xaml.cpp

@@ -51,7 +51,7 @@ UnitConverter::UnitConverter() :
 {
     InitializeComponent();
 
-    //adding ESC key shortcut binding to clear button
+    // adding ESC key shortcut binding to clear button
     clearEntryButtonPos0->SetValue(Common::KeyboardShortcutManager::VirtualKeyProperty, Common::MyVirtualKey::Escape);
 
     m_layoutDirection = LocalizationService::GetInstance()->GetFlowDirection();
@@ -278,7 +278,7 @@ void UnitConverter::AnimateConverter()
 void UnitConverter::OnValueSelected(_In_ Platform::Object^ sender)
 {
     auto value = safe_cast<CalculationResult^>(sender);
-    //update the font size since the font is changed to bold
+    // update the font size since the font is changed to bold
     value->UpdateTextState();
     safe_cast<UnitConverterViewModel^>(this->DataContext)->OnValueActivated(AsActivatable(value));
 }