More Bugfixes from Side Nav (#1162)

* Fixed a bug where the bottom of the page could be cut off

* Adjusted all the headings to h2, which looks better

* Refactored GetSeriesDetail to actually map the names inside the code so the UI just displays.

* Put in some basic improvements to OPDS by using Series Detail type layout, but this only reduces one click.

* Fixed a bug where offset from scrollbar fix causes readers to be cutoff.

API.Tests/Services/SeriesServiceTests.cs

@@ -202,7 +202,7 @@ public class SeriesServiceTests
 
         Assert.NotEmpty(detail.Volumes);
         Assert.Equal(2, detail.Volumes.Count()); // Volume 0 shouldn't be sent in Volumes
-        Assert.All(detail.Volumes, dto => Assert.Contains(dto.Name, new[] {"2", "3"}));
+        Assert.All(detail.Volumes, dto => Assert.Contains(dto.Name, new[] {"Volume 2", "Volume 3"})); // Volumes get names mapped
     }
 
     [Fact]