Use Hamcrest assertions instead of JUnit in webserver/jersey (helidon-io#1749) (helidon-io#5113)

Author: Captain1653

webserver/jersey/src/test/java/io/helidon/webserver/jersey/JerseyExampleResource.java

@@ -41,7 +41,8 @@
 import jakarta.ws.rs.core.StreamingOutput;
 import jakarta.ws.rs.core.UriInfo;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 /**
  * The JerseyExampleResource.
@@ -149,7 +150,7 @@ public Response checkSequenceStream(InputStream inputStream, @QueryParam("length
         String content = new String(inputStream.readAllBytes());
 
         try {
-            assertEquals(JerseySupportTest.longData(length).toString(), content);
+            assertThat(content, is(JerseySupportTest.longData(length).toString()));
         } catch (Throwable e) {
             streamException = e;
             throw new IllegalStateException("NOT EQUALS");

webserver/jersey/src/test/java/io/helidon/webserver/jersey/JerseySupportTest.java

@@ -42,7 +42,6 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.is;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 /**
  * The JerseySupportTest.
@@ -222,7 +221,7 @@ public void longPostNotFound() {
             // in this case the test is a no-op.
             return;
         }
-        assertNotNull(response);
+        assertThat(response, notNullValue());
         doAssert(response, null, Response.Status.NOT_FOUND);
     }