Add ignore keyword list to CommentedOutCode

### Prerequisites

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

### Rule to improve

CommentedOutCode

### Improvement description

CommentedOutCode detects code in comments like:

`foo.CheckCondition({var}param);
`

I'd like this {var} not to match with this rule.

### Rationale

We often use {var} comment to indicate the 'param' may be chanegd.
In this case, CheckCondition function is defined blow:

```
procedure CFoo.CheckCondition(var ACode: Integer);
begin
// do something
end;
```

On the other hand, this {var} may be a code to be detected.
So, I wish I could add an Ignore-Keyword-List to CommentedOutCode rule.

{out} is also frequently used for the same reason.