Enforce unique result in list-fix-paths

[TobiasNx]

Resolves #686.

@dr0i fixed the error could you help me with adding a test.

[dr0i]

@TobiasNx look at ther error:

Execution failed for task ':metafix:checkstyleMain'.
A failure occurred while executing org.gradle.api.plugins.quality.internal.CheckstyleAction
Checkstyle rule violations were found. See the report at: file:///home/runner/work/metafacture-core/metafacture-core/metafix/build/reports/checkstyle/main.html
Checkstyle files with violations: 1
Checkstyle violations by severity: [error:4]

You may just have put some extra spaces or somethin along the line.

[TobiasNx]

Thanks to @blackwinter the checkstyle is not failing anymore. @dr0i can you help me with tests?

[TobiasNx]

@dr0i you changed the option here: 53c2e6b#diff-169b6a53d763d640ae1f135fea90ead61c4f2219219ab9539d8c21d0390aeebcR62

This makes the result no fix paths anymore. You could not use it anymore in a fix transformation, we need the index position for that. e.g. c.2 is a fix path, but c is only the path to the array, you could not use copy_field("c","new_field") to only copy this value, you would use copy_field("c.2","new_field") to only copy the specific value.

PS: This also puts two changes into one commit that should have been two commits.

[dr0i]

I've modified the test, see d5ff80d.
If it's good the commits can be squashed.

[TobiasNx]

I think I understand how to adjust the test now. Can I add another record to the test like this. Duplicate elements are already tested. I need to test duplicate field/values in multiple records. See: #686 (comment)

    private void processRecord() {
        finder.setReceiver(receiver);
        finder.startRecord("1");
        finder.literal("a", "An ETL test");
        finder.literal("b", "");
        finder.literal("b", "Dummi");
        finder.literal("b", "Dog");
        finder.literal("c", "");
        finder.literal("c", "ETL what?");
        finder.endRecord();
        finder.startRecord("2");
        finder.literal("a", "An another test");
        finder.literal("b", "");
        finder.literal("b", "Dummi");
        finder.literal("b", "Dog");
        finder.literal("c", "");
        finder.literal("c", "ETL what?");
        finder.endRecord();
        finder.closeStream();
    }
``

[dr0i]

you can add the test - why shouldn't you?

[TobiasNx]

Done

[dr0i]

As discussed: readd the Mockito test and adapt the test to be successful, then assign @blackwinter for review.