tests(list): migrate preexisting test

[ee7]

Migrate the preexisting test for lists, altering it to reflect that assignment no longer performs a copy.

From the Con4m language reference:

libcon4m/doc/reference.md

Lines 227 to 229 in b4fdc8e

	Builtin types are either _value types_ or _reference types_. Value
	types are limited to numeric and boolean types that can be represented
	in 64-bits or less.