Add template resolver for a new location for uswds templates

[cy-by]

• Ticket #185770089
• Starter app PR

Question for reviewer:
I had to create both ThymeleafConfigurationUnloadedTest and ThymeleafConfigurationLoadedTest in separate files so that I could load different application properties. Ideally I would like it to be in one file, maybe with nested classes, but I wasn't able to figure it out. If you have suggestions that would improve this, I'm very open to it.

[spokenbird]

I might reword this. If I'm correct, it's actually setting the UWDS resolver to be used over the default, meaning that enabling it would turn on the USWDS resolver, but those templates will now replace the same ones from the Honeycrisp resolver? Meaning that turning this on will switch your application to using USWDS styles and components instead of Honeycrisp styles and components.

[spokenbird]

I ran into this same issue when setting application properties with regards to whether or not to scan file uploads with ClamAV. I could not figure out a way to have different application properties on a test by test basis, even with nested classes.

I hate that it has to be done this way as two seperate tests, and I hate even more that I have to ask:

Do we want a third test that tests it defaults to Honeycrisp when no application property is set?