* forward-port AQL optimizations from 3.3
* fix restrict-to-single-shard rule
* added tests for specific cases
* ModificationNodes now can know if they are restricted or not
* OptimizerRule now updates the ModificationNode instead of setting ownName on remote node.
* The DBServerEngine container now only sends a subset of snippets (those which are relevant) It is able to restrict any part of the query to a certain shard or even a list of shards
* ExecutionEngine CreateBlocks in ClusterMode now returns Result instead of throwing.
* Adapted Coordinator side to a bitter mapping of RemoteNode => QuerySnippets. This is still ongoing work.
* Fixed Coordinator enginecontainer test and finisehd implementation of EngineInfoContainerDBServer. Seems to work so far, need to adapt test to prove it.
* Adapted test for modification nodes and restrict to shard.
* restrictTo can now be de-/serialized on Modification Nodes
* Fixed Community Compile Error
* Added a test for Indexes/EnumerateCollection nodes
* EnumerateCollection and IndexNode now have options to be restricted to a single shard, opt rule not yet updated
* DBServer part of planning now checks Enumerate and IndexNodes for single shard optimization
* Added tests for simple single shard optimization on IndexNodes
* Adapted optimzierrule for SingleShard optimierung on IndexNodes
* Fixed an issue with externally restricted shard ids in combination with shard_id based optimization
* Added a test for multiple single shard optimizations on the same collection
* Removed collection/Shard duplicate check of optimize to single shard rules
* Updated Explainer to handle optimize to single shard
* Let more tests pass an optimized AQL variant
* Temporarily disabled a tests that can only be solved after some work in transaction
* reduce extractions to projections
* recycle string buffers in SocketTask
* micro optimizations for mmfiles indexes
* added special lookup function for _key
* moved function into the correct file
* speed up key buffer allocations a bit
* added noexcept specifier
* correctly name variable
* explicitly move bounds
* fix and speedup from/toPersistent functions
* reuse string from ManagedDocumentResult for multiple lookups
* use move-assign
* a bit less work for single server
* speedup AQL function HASH
* single fetch optimization
* performance optimization for the case when no documents need to be returned
* make reduce-extraction-to-projection a RocksDB-only optimizer rule
* cppcheck
* try to fix compile error on MacOS
* bug fix for MacOSX
* missing namespace (in Windows compile)
* reduce extractions to projections
* recycle string buffers in SocketTask
* micro optimizations for mmfiles indexes
* added special lookup function for _key
* moved function into the correct file
* speed up key buffer allocations a bit
* added noexcept specifier
* correctly name variable
* explicitly move bounds
* fix and speedup from/toPersistent functions
* reuse string from ManagedDocumentResult for multiple lookups
* use move-assign
* a bit less work for single server
* speedup AQL function HASH
* single fetch optimization
* performance optimization for the case when no documents need to be returned
* make reduce-extraction-to-projection a RocksDB-only optimizer rule