[#292] Morley logs and error reporting in DAP

Description

Problem: Running of the contract may produce trace messages, and also fail with an error. These should be reported to VSCode using OutputEvent.

Solution: Change handleRequest so that a NextRequest generates an OutputEvent in case of a log or an error. Also, in case of an error, it's now reported an "exception" in a StoppedEvent as well.

Related issue(s)

Resolves #292 (closed)

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