Add conditional expressions in explicit-length-check rule

[christophehurpeau]

Add ConditionalExpression in the rule explicit-length-check, allowing to check this kind of code :

const foo = [].length === 0 ? null : undefined;

Before, only IfStatements where checked.

It does create a breaking change, do you want to add an option for it ?

[sindresorhus]

It does create a breaking change, do you want to add an option for it ?

No, I'll just do a major release. Most things regarding linting is a breaking change.