Check to detect unnecessary if/else condition nesting

[Gama11]

Would be nice to detect code like this:

if (conditionA) {
    if (conditionB) {
        doSomething();
    }
}

which would be better written as:

if (conditionA && conditionB) {
    doSomething();
}

or

if (conditionA) {
    doSomething();
}
else {
    if (conditionB) {
        doSomething();
    }
}

which could use else if.

Not sure if this should be a new check or be covered by SimplifyBooleanExpression.