Feature/serialization exe (#442)

* Initial changes to have serialization generate its own .exe

* Removed additional project from sln file

* remove all references to removed temporary project

* Moved shared contracts into own dll and fixed imports. Addressed PR comments

* Undid having a separate contracts project since that'll be a task for later on. Moved dbcellvalue and saveresultsrequest to Hosting, where they will be imported and shared by the service layer and serialization projects

* Switched backslashes in project reference in csproj file to forward slashes for consistency

* Moved necessary contracts back to service layer. Refactored CommandOptions to reduce code duplication. Addressed miscellaneous PR suggestions

* Accidentally left these files out of previous commit

* Initialized loggers for serialization and credentials with the logging directory provided by the cmd line arg, if there is one

* Changed default log directory paths for serialization and credentials. Removed unnecessary cast and added a copyright

* Changed name of generated executable for serialization service

* removed unnecessary object cast

* removing unnecessary imports and addressing other PR comments

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/DataStorage/SaveAsExcelFileStreamWriterHelper.cs

@@ -3,12 +3,12 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts;
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Compression;
 using System.Xml;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage
 {