Enable database switching with :use xx in multi-statement command

[oskarhane]

Added E2E tests

Make sure you enable multi-stament.

Test script:

1. Create databases
   :use system
2. CREATE DATABASE test1; CREATE DATABASE test2;

:use neo4j;
:param x => 1;
:unknown;
:use test1;
CREATE (:Test1);
:use test2;
CREATE (:Test2);

Check contents of the different databases. This is what the E2E test does.

[huboneo]

@oskarhane maybe I am doing something wrong but this is not working:

:use foo

CREATE(n:foo) 
RETURN n

:use neo4j
MATCH (p:Person) RETURN p

:use foo
CREATE (z:bar) 

I get A database with that name not found.

[oskarhane]

You need semi-colons to separate statements @huboneo

[huboneo]

functional testing OK. Feel that I dont have enough context to understand the code changes. LGTM