[#53] Use typed addresses in `originate` and `call`

Description

Problem: Morley.Nettest's originate and call should behave like their counterparts from Integrational and use typed addresses instead of untyped ones.

Solution: Changed originate to return a typed address and call to take a typed address. Also removed unnecessary Show constraint from contract parameter.

Related issue(s)

Resolves #53 (closed)

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