`VariableInitialization` rule should treat `out` parameters as uninitialized

[Cirras]

Prerequisites

• [X] This improvement has not already been suggested.
• [X] This improvement should not be implemented as a separate rule.

Rule to improve

VariableInitialization

Improvement description

Current behavior

Routine parameters are currently always considered initialized at the start of a routine.

Suggested behavior

out parameters should be considered uninitialized at the start of a routine.

Rationale

out parameters are meant to be routine results, and should never be assumed to be initialized. Indeed, if they are initialized then it's actually more of a smell (see #133).