Description
1. Add dependencies on GRPc libraries to Couchbase.csproj
2. Migrate Stellar code from Couchbase.Stellar to Couchbase
3. Migrate Couchbase.Steller.CombinationTests to Couchbase.CombinationTests
4. Migrate code from Couchbase.NetStellar to Couchbase (Cluster static methods)