Return more informative error code when incorrect JSONP JsonValue is read

The MBR reader for JSONP reads any JSON payload including a document containing a single `JsonValue` that is not a `JsonStructure`. For example, a single `JsonString`. However, most users will define a resource method as accepting a `JsonObject` or `JsonArray`, that is, a structured JSON type. Jersey will attempt to call the method, reflectively, even if the argument types do not match, resulting in an internal server error (500 error code).

There's two types of exception traces, likely depending on JIT intervention. See below (simplified as they were generated using a Helidon application):

```
Caused by: javax.ws.rs.ProcessingException: Resource Java method invocation error.
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:153)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:167)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:176)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:79)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:475)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:397)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:81)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:255)
... 14 more
Caused by: java.lang.IllegalArgumentException: argument type mismatch
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:124)
... 21 more
```

```
Caused by: javax.ws.rs.ProcessingException: Resource Java method invocation error.
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:153)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:167)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:176)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:79)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:475)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:397)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:81)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:255)
... 14 more
Caused by: java.lang.IllegalArgumentException: java.lang.ClassCastException@170c9d1d
at jdk.internal.reflect.GeneratedMethodAccessor34.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:124)
... 21 more
```

Strictly speaking, all resource methods should accept `JsonValue` but in practice that is difficult to enforce and makes the code more complicated. Instead, Jersey could catch these exceptions and report a better error code such as 400.

Start with the JSONP MBR reader and the resource-method invocation path described in the issue, then reproduce the single-JsonValue case using the supplied exception traces. Done means an incompatible JSON value produces an informative client error such as HTTP 400 instead of reaching reflective invocation and returning HTTP 500.

Written by the indexing model from the issue text.