URF_UNREAD_FIELD: should be ignored on test class fields annotated with JUnit5's @RegisterExtension

[hanleyt]

JUnit 5.1 allows you to register an extension programmatically by adding a field to your class as shown below. Similiar to JUnit4s Rule/ClassRule.

@RegisterExtension
JerseyExtension jerseyExtension = new JerseyExtension(this::configureJersey);

(apologies I haven't yet had a chance to add a failing test for this)

[ghost]

I would prefer a configurable list of annotations that that tell SpotBugs to ignore this rule for a given field.
@xmlelement and @SerializedName also define that the field value is used. And in the past, I have already written my own tools that access fields via annotations.

This would be a great thing to have.