Added Missing Microsoft.Xna.Framework.Graphics Exceptions

A couple of Microsoft.Xna.Framework.Graphics exceptions were missing in MonoGame, causing it to fail to compile in projects that referenced any of them. This PR adds the missing exceptions to allow these to at least compile in projects that use them.

Aside from that there's no functional changes here.

We also noticed a problem in Texture.GetPitch(). The fix was accidentally committed and added to this pull request, though it's still valid.