Rename spring.mvc.path-match.* and spring.mvc.content-negotiation.* properties

[wilkinsona]

#11105 added some new properties that are grouped beneath spring.mvc.path-match and spring.mvc.content-negotation. We should rename them so that there's no need for the - characters.

spring.mvc.pathmatch and spring.mvc.contentnegotation are the easy (and most obvious) options, but perhaps there's something better?

[bclozel]

👍 This is indeed an oversight on my part.
I can't find better alternatives, and those names refer to Spring MVC configuration types so in my opinion we'd better keep it that way.