Implement LOAD CSV

[rjb32]

Implement a LOAD CSV command based on Neo4j LOAD CSV ergonomics.

Constraints:

• Ideally we don't want to have variant types and lists
• Neo4J actually loads strings that have to be converted to the property types if necessary

[rjb32]

LOAD CSV query phase 1 returned that parses CSV files and returns a table of string columns.
TODO: phase 2 with LOAD CSV + MATCH, LOAD CSV + CREATE

LOAD CSV + MATCH depending on ValueHashJoin implementation
LOAD CSV + CREATE depending on WriteProcessor refactoring