Reviewers should be able to bypass validation for the variables used

[Mariano-SOes]

New suggestions are validated to check all variables from the original string are used in the suggestion.

Reviewers should have a way to bypass that validation for special cases, when one or more variables won't be included in the translation. E.g. a variant is better translated using a word instead of the number returned by a variable, or when a variables returns a link to a MSE/blog post that has a been translated in the per-site Meta.

If a user believes a translation should not use all variables, the proposed method is to post in the per-site Meta so the reviewer can handle that particular string.