Validation for duplicate Qute TemplateExtension

[angelozerr]

Given those 2 classes which defines the same foo TemplateExtension:

package util;

import io.quarkus.qute.TemplateExtension;

public class CLassA {

    @TemplateExtension
    public static boolean foo() {
        return true;
    }
}

and

package util;

import io.quarkus.qute.TemplateExtension;

public class CLassB {

    @TemplateExtension
    public static boolean foo() {
        return false;
    }
}

We should study the behavior of the Qute (perhapsit reports some error when the Qute application is compiled). According the behavior we should perhaps reporting error like duplicate foo TemplateEtension.