improve java 17 build support

[landryb]

Description

as of now mapstore 2 doesnt build with java 17.

a first step is to use a more recent version of the maven-war plugin, using 3.4.0 instead of 2.1.1.

this allows a build with -DskipTests to succeed.

the tests themselves fail to build with the same failure:

java.lang.NoClassDefFoundError: Could not initialize class org.mockito.internal.creation.jmock.ClassImposterizer$3
        at org.mockito.internal.creation.jmock.ClassImposterizer.createProxyClass(ClassImposterizer.java:85)
        at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:62)
        at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:56)
        at org.mockito.internal.creation.CglibMockMaker.createMock(CglibMockMaker.java:23)
        at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:26)
        at org.mockito.internal.MockitoCore.mock(MockitoCore.java:51)
        at org.mockito.Mockito.mock(Mockito.java:1243)
        at org.mockito.Mockito.mock(Mockito.java:1120)
        at it.geosolutions.mapstore.LoadAssetControllerTest.testLoadPngAsset(LoadAssetControllerTest.java:152)
        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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)

this has probably something to do with an update of the mockito framework ?

[landryb]

updating mockito to 4.0.0 (cf 4c3c2b8) seems to fix java 17 compat, here mvn clean install succeeds now.

[landryb]

cf #6935 for a requirements update if java 17 is deemed acceptable. i know mapstore runs fine with java17, and #9851 might allow to build with java17.