Log when recover index samples on startup
Log manual triggering of index sampling
Code cleanup
Log when evicting stale plans
Fix: unused imports
Internal server cleanup

This does not go quite as far as it should, but goes a little way towards
cleaning up stray items in the server. The package structure needs a bigger
cleanup, but that job is much more complex as several interfaces in the
internal packages are exposed as public API and are thus unmoveable directly.

- Remove unused services and classes
- Move REST service classes into rest package
Fix for docs bug in import-tool manpage, and an additional example.
Refactored test code
Clean up of cardinality estimation

* Mostly test clean up around AssumeIndependenceQueryGraphCardinalityModelTest
* Also tweaking of the selectivity of relationship uniqueness predicates
Handling of var length in the independence cardinality model
Merge pull request #3478 from davidegrohmann/2.2-log-stats-event

Log events related to statistics
Merge pull request #3511 from nawroth/import

Fix for docs bug in import-tool manpage, and adding an additional example.
Fix error in UNWIND docs.
Generalize IndexSamplingJobQueue

- fix pollAll semantics to return values wrt insertion order
Merge pull request #3513 from systay/varlength-cardinality

Var-length cardinality estimation
Args: Make it possible to distinguish options from flags to make parsing more robust

With this change, parsing flags such as `-recovery` will never consume any consecutive symbols
in the list of arguments, such as symbols meant to be orphaned arguments.
Consistency checker fails when recovery needed but '-recovery=false' specified
After transactions were applied in recovery NeoStore is asked to rebuild id generators
Merge pull request #3516 from nawroth/2.0-unwind

Fix error in UNWIND docs.
Merge pull request #3507 from jakewins/2.1-server-clean

Internal server cleanup