RFR: 8342627: Create Eclipse project files for jdk.jsobject

[Andy Goryachev]

Added eclipse project files.

The project is named `jsobject` instead of jdk.jsobject, similarly to how the other projects are named "base", "controls", ... instead of their full module names.

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Commit messages:
 - eclipse files

Changes: https://git.openjdk.org/jfx/pull/1621/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1621&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342627
  Stats: 16 lines in 3 files changed: 15 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1621.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1621/head:pull/1621

PR: https://git.openjdk.org/jfx/pull/1621