Improve editing of multiline pastes

[gitbuda]

When a user pastes command from, e.g. docs:

LOAD CSV FROM "/path-to/people_nodes.csv" WITH HEADER AS row
CREATE (n:Person {id: row.id, name: row.name});

it's possible to edit only the last line. A solution is to paste line by line, but that's very inconvenient when there are many lines (3+).