[jfx17] RFR: 8271230: Remove obsolete test classes and data files from 3DViewer sample

[Ambarish Rapte]

On Sat, 24 Jul 2021 12:45:04 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

> Remove the obsolete `apps/samples/3DViewer/src/test` directory from the 3DViewer sample, including two test classes that don't run and a set of data files that won't load. This is a follow-on cleanup bug to [JDK-8269259](https://bugs.openjdk.java.net/browse/JDK-8269259).
> 
> NOTE: this is targeted to `jfx17`.

Looks good, verified that 3DViewer test builds and runs properly after removing these files.

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Marked as reviewed by arapte (Reviewer).

PR: https://git.openjdk.java.net/jfx/pull/587