Add get flow and basic tests.

Author: mdaigle

src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj

@@ -1025,6 +1025,7 @@
     <PackageReference Include="System.Buffers" Version="$(SystemBuffersVersion)" />
     <PackageReference Include="System.Security.Cryptography.Pkcs" Version="$(SystemSecurityCryptographyPkcsVersion)" />
     <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonVersion)" />
+    <PackageReference Include="System.Threading.Channels" Version="$(SystemThreadingChannelsVersion)" />
   </ItemGroup>
   <Import Project="$(CommonSourceRoot)tools\targets\GenerateResourceStringsSource.targets" />
   <Import Project="$(NetFxSource)tools\targets\GenerateThisAssemblyCs.targets" />

src/Microsoft.Data.SqlClient/src/Microsoft/Data/ProviderBase/DbConnectionInternal.cs

@@ -97,6 +97,8 @@ internal DbConnectionInternal(ConnectionState state, bool hidePassword, bool all
 
         #region Properties
 
+        internal DateTime CreateTime => _createTime;
+
         internal bool AllowSetConnectionString { get; }
 
         internal bool CanBePooled => !IsConnectionDoomed && !_cannotBePooled && !_owningObject.TryGetTarget(out _);