Merge | DbConnectionOptions (The Rest Of It) (#3388)

* Lazily merge the platform specific code into DbConnectionOptions.cs

* Addressing @edwardneal's comments

Author: benrr101

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -802,7 +802,6 @@
       <Link>System\Diagnostics\CodeAnalysis.cs</Link>
     </Compile>
 
-    <Compile Include="Microsoft\Data\Common\ConnectionString\DbConnectionOptions.netcore.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SqlAppContextSwitchManager.NetCoreApp.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SqlBulkCopy.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SqlConnectionFactory.AssemblyLoadContext.cs" />

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/Common/ConnectionString/DbConnectionOptions.netcore.cs

@@ -950,7 +950,6 @@
     </Compile>
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="Microsoft\Data\Common\ConnectionString\DbConnectionOptions.netfx.cs" />
     <Compile Include="Microsoft\Data\Common\DBConnectionString.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SqlBulkCopy.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SqlClientWrapperSmiStream.cs" />