New rule: Dead stores should be removed

[jgardn3r]

Prerequisites

• This rule has not already been suggested.
• This should be a new rule, not an improvement to an existing rule.
• This rule would be generally useful, not specific to my code or setup.

Suggested rule title

Variables shouldn't be unnecessarily assigned

Rule description

Dead stores refer to assignments made to local variables that are subsequently never used or immediately overwritten. Such assignments are unnecessary and impact the clarity and potentially performance of the code. Removing them improves clarity, intentionality, and readability.

For example:

function Test: Integer;
begin
  var I := 10; // This assignment is useless
  I := 20;
  Exit(I);
end;

Rationale

This rule will limit extraneous variable assignment.