RFR: 8243115: Unregister bindings when unbind called multiple times

[John Hendrikx]

This fixes a bug where the first call to unbind would clear the internal invalidation listener used, resulting in
subsequent unbind calls to be no-ops, unless bind was called again first.

I had to rewrite the parameterized test slightly as Parameterized will only call the parameters method once, and my new
test modifies the internal state of the bindings used as parameters (by doing some unbind calls) which was making other
tests fail.

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Commit messages:
 - 8243115: Unregister bindings when unbind called multiple times

Changes: https://git.openjdk.java.net/jfx/pull/198/files
 Webrev: https://webrevs.openjdk.java.net/jfx/198/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8243115
  Stats: 206 lines in 9 files changed: 147 ins; 43 del; 16 mod
  Patch: https://git.openjdk.java.net/jfx/pull/198.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/198/head:pull/198

PR: https://git.openjdk.java.net/jfx/pull/198