Reorg: move files from root to WEB directory.

[TimothyMothra]

microsoft/ApplicationInsights-dotnet#1214

Step 1. Reorganize individual repos. This is to ensure that there are no conflicting directories or file names and to guarantee no conflicts when migrating source. This will require some minor changes to existing build definitions.

Changes
Update Directory

• EnlistmentRoot stays in root directory
• Add SourceRoot
• Update Directory.Build.props
• Update NuGet.config (add a level to ..\packages)
• All NetFramework projects (Tests) (add a level to ..\packages)

Update directory in build tasks:

• Clean script
• StrongName Verification script (enable & disable)
• Build directory "dirs.proj"
• GenerateReleaseMetadata script
• SDL script files
• Docker scripts
• Kill iis express script
• Disable NugetRestore task (alt: could change path to config)