Fix delete before write for ADO.NET providers

Author: ReubenBond

src/AdoNet/Orleans.Persistence.AdoNet/Storage/Provider/AdoNetGrainStorage.cs

@@ -165,6 +165,15 @@ public async Task ClearStateAsync<T>(string grainType, GrainId grainReference, I
                     grainState.ETag);
             }
 
+            if (!grainState.RecordExists)
+            {
+                await ReadStateAsync(grainType, grainReference, grainState).ConfigureAwait(false);
+                if (!grainState.RecordExists)
+                {
+                    return;
+                }
+            }
+
             string storageVersion = null;
             try
             {
@@ -198,13 +207,10 @@ public async Task ClearStateAsync<T>(string grainType, GrainId grainReference, I
             }
 
             const string OperationString = "ClearState";
-            if (storageVersion != null)
+            var inconsistentStateException = CheckVersionInconsistency(OperationString, serviceId, this.name, storageVersion, grainState.ETag, baseGrainType, grainId.ToString());
+            if (inconsistentStateException != null)
             {
-                var inconsistentStateException = CheckVersionInconsistency(OperationString, serviceId, this.name, storageVersion, grainState.ETag, baseGrainType, grainId.ToString());
-                if (inconsistentStateException != null)
-                {
-                    throw inconsistentStateException;
-                }
+                throw inconsistentStateException;
             }
 
             //No errors found, the version of the state held by the grain can be updated and also the state.