Fix several viewport issues (#1045)

* Fix some FOV calculation viewport issues:
-Avoid calculating FOV if we've got an invalid viewport
-Don't override game mode FOV, let the active camera components manage it instead

* Fix viewport font positioning

This updates code in a few places to respect an API change/fix made to AtomFont - also switched the default value of m_virtual800x600ScreenSize to false as it's really behavior you want to opt into

* Don't activate CameraComponentController when in the Editor / not in game mode

Gems/AtomLyIntegration/AtomViewportDisplayInfo/Code/Source/AtomViewportDisplayInfoSystemComponent.cpp

@@ -162,7 +162,7 @@ namespace AZ::Render
         m_drawParams.m_hAlign = AzFramework::TextHorizontalAlignment::Right;
         m_drawParams.m_monospace = false;
         m_drawParams.m_depthTest = false;
-        m_drawParams.m_virtual800x600ScreenSize = true;
+        m_drawParams.m_virtual800x600ScreenSize = false;
         m_drawParams.m_scaleWithWindow = false;
         m_drawParams.m_multiline = true;
         m_drawParams.m_lineSpacing = 0.5f;