Fixes a cache poisoning issue.

- The new dense nodes relationship loading had a bug in it where
  if you asked it to load relationships of a type it did not have it
  would incorrectly mark the node as having no relationships at all.
  This corrects that.
Add cardinality estimation to Semi Apply
Fix Load CSV queries to use indexes when possible
Merge pull request #2297 from jakub-/semi-apply-cardinality-estimation

Add cardinality estimation for Semi Apply
Merge pull request #2298 from jakub-/load-csv-schema-indexes

Fix Load CSV queries to use indexes when possible
Add ORDER BY planning
Merge pull request #2283 from jakewins/2.1-cachepoison

Fixes a cache poisoning issue.
Merge pull request #2299 from jakub-/sort

Add ORDER BY planning
Remove unnecessary extra cartesian product check in Ronja
Add support for SelectOrSemiApply