Angular ESLint Utils

[timdeschryver]

This issue is here to remind us to take a look at the Angular ESLint Utils (angular-eslint/angular-eslint#676) and maybe refactor some of our code to use those utils where possible.

[timdeschryver]

@rafaelss95 I noticed you've creating an issue at eslint-rxjs to allow suggestions in fromFixture.
My idea was to use the test utils from the angular-eslint, do you have an opinion about this?

[rafaelss95]

Yes, I opened a problem there because it would help us at the moment, since we are currently using fromFixture, but I have no objections to using convertAnnotatedSourceToFailureCase.