Remove virtual and pimpl from single node

Summary:
This diff removes: `SingleNodeRecoveryTransactions`, `TypemapPack`
It also removes virtual and/or pimpl from: `SingleNodeCounters`,
`StorageGcSingleNode`, `SingleNodeConcurrentIdMapper`,
accessors (revert D1510), transaction engine, `GraphDbAccessor`, `GraphDb`

Reviewers: msantl, teon.banek

Reviewed By: msantl, teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1639

tests/unit/bolt_encoder.cpp

@@ -164,7 +164,7 @@ TEST(BoltEncoder, VertexAndEdge) {
   output.clear();
 
   // create vertex
-  database::SingleNode db;
+  database::GraphDb db;
   auto db_accessor = db.Access();
   auto va1 = db_accessor->InsertVertex();
   auto va2 = db_accessor->InsertVertex();