Fix null query parameter handling in generated RestEasy Reactive clients

[kdubb]

Also adds missing query handling tests.

The tests for using a Map<> as a query param via the RestQuery annotation are commented out. This is because I cannot figure out how to get these to work. If I uncomment them then the Quarkus refuses to build the client with an error of Failed to find converter for java.util.Map; I am not sure if this is itself a bug or user error.

[kdubb]

@geoand This is a fix for #23876 that I commented on today. Note that my comments were wrong lol.

[geoand]

Map is currently not supported for @RestQuery (or any of the other types actually). I do think it would be useful to have (and not that difficult to add), but let's please remove the commented part of the code for now.

[kdubb]

Ok. I'm confused by #24783 and its associated issue #24764 that seem to say & implement exactly that.

[geoand]

That is for the client, not the server

[kdubb]

Yes. This PR is for the client and the PR/Issue I referenced are about using a Map in the client.

I must be completely missing something here lol.

[geoand]

I must be completely missing something here lol.

The failure you are getting is from the Server where you are trying to use Map to read all query params - that's what's not supported.

[kdubb]

I knew I was missing something obvious...

I reinstated the tests for map but I'm using UriInfo on the server to extract all the query parameters. This way we're still testing the client's map (or null map) support.

[geoand]

Great, thanks!