Make shared strings public to enable FieldWorks SDK style builds (#346)

- In the old build system somehow using the same namespace in
   the FieldWorks code and in this library was enough to get internal
   access to the strings resources. Update these strings to public
   so that FieldWorks can use them in its UI.

Author: jasonleenaylor

src/SIL.LCModel.FixData/SIL.LCModel.FixData.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>net462;netstandard2.0</TargetFrameworks>
@@ -27,7 +27,7 @@ SIL.LCModel.FixData provides functionality to fix errors in a FieldWorks data XM
 
   <ItemGroup>
     <EmbeddedResource Update="Strings.resx">
-      <Generator>ResXFileCodeGenerator</Generator>
+      <Generator>PublicResXFileCodeGenerator</Generator>
       <LastGenOutput>Strings.Designer.cs</LastGenOutput>
     </EmbeddedResource>
   </ItemGroup>