Fix: Correctly isolate aggregates from expressions that introduce interior scopes (reduce, fitler, extract, comprehensions)

signed-off-by: Jakub Wieczorek <jakub.wieczorek@neotechnology.com>
Merge pull request #2720 from boggle/2.1-maint

Fix: Correctly isolate aggregates from expressions that introduce interi...
Merge remote-tracking branch 'upstream/2.0-maint' into 2.1-maint

Conflicts:
	community/cypher/cypher-compiler-2.0/src/main/scala/org/neo4j/cypher/internal/compiler/v2_0/ast/convert/StatementConverters.scala
	community/cypher/cypher-compiler-2.0/src/test/scala/org/neo4j/cypher/internal/compiler/v2_0/parser/CypherParserTest.scala
	community/cypher/cypher/src/test/scala/org/neo4j/cypher/MergeNodeAcceptanceTest.scala