false positive on no-whitespace-for-layout about ember-template-lint

[bmish]

Currently, as the rule doc says, this rule checks any text nodes for excess whitespace, including text inside or outside attributes. But I think it's a fair question to ask if the rule should be checking the values of arbitrary attributes. Arguably, the class attribute could be fair-game for an excess whitespace check, as it's an attribute we know shouldn't have (or at least doesn't need) excess whitespace in it, but attribute values aren't used for the page layout, so checking this may not align with the goal of the rule.

I didn't immediately see a justification for this behavior in the original rule PR #819. Maybe @MelSumner has some context on whether this is intended behavior.

[MelSumner]

@bmish I'd be okay with excluding attribute values from these checks, that seems reasonable.