RFR: 8251353: Many javafx scenegraph classes have implicit no-arg constructors [v3]

[Bhawesh Choudhary]

> Added missing explicit no-arg constructors to classes in package javafx.scene, javafx.css and javafx.stage.

Bhawesh Choudhary has updated the pull request incrementally with one additional commit since the last revision:

  Reverted changes for class Selector and ShapeConverter as per review comment

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Changes:
  - all: https://git.openjdk.java.net/jfx/pull/283/files
  - new: https://git.openjdk.java.net/jfx/pull/283/files/16d8b9ad..38a7551d

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/283/webrev.02
 - incr: https://webrevs.openjdk.java.net/jfx/283/webrev.01-02

  Stats: 14 lines in 2 files changed: 0 ins; 14 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/283.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/283/head:pull/283

PR: https://git.openjdk.java.net/jfx/pull/283