IGNITE-22381 Fix java8 and java11 compilation

[alex-plekhanov]

• Moved gatling-ext module under java-11+ profile (some dependencies of this module compiled with java-11 and can't be recognized by java-8).
• For java-11+ profile target compiler version is set to 11 (the same we have for the parent ignite project, even if we try to compile with 1.8 target, compiled classes still can't be used by java-8, but target=1.8 or release=1.8 brokes usage of add-opens).
• Gatling maven plugin execution is disabled when -DskipTest or -Dmaven.test.skip=true parameters are passed to maven (currently, this plugin always executed on test phase, even if we disable tests explicitely).
• Options --add-opens also added to java-11+ (They are not mandatory by java-11, but they remove warnings about reflection usage).

[skorotkov]

I would suggest to not move the gatling-ext as a whole but the examples sub-module only.

It's the examples sub-module who use the gatling-maven-plugin which is built with jdk-11.

In other words modify the modules/gatling-ext/pom.xml moving the examples to java-11+ profile as

    <modules>
        <module>gatling-plugin</module>
    </modules>

    <profiles>
        <profile>
            <id>java-11+</id>
            <activation>
                <jdk>[11,)</jdk>
            </activation>
            <modules>
                <module>examples</module>
            </modules>
        </profile>
    </profiles>

[alex-plekhanov]

Unfortunately, gatling-plugin still requires java11 to run tests, it can be compiled on java8, but can't be used and will be failed on TC.