ember/no-test-module-for catches too many things

our test suite has a bunch of functions that wraps `module()`. The `ember/no-test-module-for` rule flags all of these as problematic. (The rule is just looking for functions starting with `moduleFor`). Not clear if this is intentional or not, but maybe the rule should also check where the function was imported from `ember-qunit` before flagging?

https://github.com/ember-cli/eslint-plugin-ember/blob/d2716993c87b2c38f4869572c43e78bbdf819921/lib/rules/no-test-module-for.js#L84

An alternative for us is to just go and rename these functions so they don't start with moduleFor (or take a much harder look at why they exist in the first place... which makes upgrading less fun).

Thoughts?