[REQ] [JAVA] [SPRING] Handle arrays of strings as Mono<List<String>> instead of Flux<String> when using reactive types

[TMRGZ]

Is your feature request related to a problem? Please describe.

When the describing the operation that returns an array of strings, the reactive Spring generator generates Flux<String>

This issue is the equivalent to this one from the Java Webclient: #7118

Describe the solution you'd like

An equivalent solution that returns a Mono<List<String>>

Additional context

I'll provide a draft PR inspired on the one that fixes the problem for the Java WebClient