Refactor project template tests to make them more consistent and reduce repetition

From PR comment: https://github.com/dotnet/aspnetcore/pull/42143#issuecomment-1154757891

> @HaoK: Not strongly suggesting you do this, but seeing all the instances of SkipOnHelix, and all the logic around computing launch settings. I started wondering if the https tests were split into derived (class i.e. MvcHttpsTemplateTest), it might reduce some of the duplication, as you could have a property controlling whether all the tests were doing Https or not rather than having 2 permutations of every test, and could move the SkipOnHelix to the https class as well. Food for thought anyways

> @DamianEdwards: Yeah this is kind of the problem with these tests is they grow so organically over time and it's easiest to just copy/paste/add-dimension, not to mention that often when there's a Helix issue the tests get tactically refactored to allow disabling only the affected tests on Helix. They could certainly be refactored in places but honestly there's a time/effort-element here as well.

> @HaoK: Yeah I think maybe we should just have a chore/tracking issue to refactor the tests, definitely shouldn't do it in this PR, but I think these are getting near that unwieldy point where a refactor pass might make sense soon, especially if any more permutations are added