RFR: 8267418: IntelliJ build and test of JavaFX does not work [v4]

[Marius Hanl]

> ~~Question: I was wondering, should I create a ticket for this as well? Given the fact that I don't have an https://bugs.openjdk.java.net account, I need to use the official bug reporting tool, which looked a bit overkill to me since someone needs to check my created ticket, while this PR is only affecting the IntelliJ IDE with OpenJFX and not the JavaFX platform directly.~~
> EDIT: Thank you, Kevin. :)
> 
> This PR fixes the errors you get when cloning and working with OpenJFX in IntelliJ IDE:
> - The **.idea/misc.xml** is modified to use **JDK_11** as language level instead of JDK_8. 
> -> This is the language level shown inside the **Project Structure**. (File -> Project Structure...)
> - The **.idea/base.iml, .idea/controls.iml, .idea/fxml.iml, .idea/web.iml, .idea/graphics.iml** are modified to include/recognize the shims (as test resource, this is very similar to the configuration inside the .classpath file from Eclipse)
> - EDIT: The projects are now recognized by IntelliJ-gradle (**.idea/gradle.xml**, **.idea/compiler.xml**)
> 
> **-> With this, I can run all normal tests with IntelliJ**
> 
> ### What I couldn't fix yet (When I tried, it looked like IntelliJ is overriding the settings on next gradle reload): 
> - IntelliJ is not detecting javafx.graphic inside the shims
> - All javafx.* dependencies are not found for the system tests
> 
> **-> If someone has a solution, feel free to comment :)**

Marius Hanl has updated the pull request incrementally with one additional commit since the last revision:

  Reverted whitespace made by IntelliJ

-------------

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/506/files
  - new: https://git.openjdk.java.net/jfx/pull/506/files/e6963285..591bdacf

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=506&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=506&range=02-03

  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jfx/pull/506.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/506/head:pull/506

PR: https://git.openjdk.java.net/jfx/pull/506