RFR: 8276490: Incorrect path for duplicate x and y values, when path falls outside axis bound

[Abhinay Agarwal]

PathElements were skipped in AreaChart if the data point were outside axis bounds and had duplicate value for either x or y. This is now fixed with this PR.

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Commit messages:
 - Remove trailing whitespace
 - Remove unwanted import
 - Update tests
 - 8276490: Incorrect path is drawn if visible area of the chart is smaller than actual size

Changes: https://git.openjdk.java.net/jfx/pull/667/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=667&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8276490
  Stats: 63 lines in 2 files changed: 58 ins; 1 del; 4 mod
  Patch: https://git.openjdk.java.net/jfx/pull/667.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/667/head:pull/667

PR: https://git.openjdk.java.net/jfx/pull/667