RFR: JDK-8303443: IGV: Syntax highlighting and resizing for filter editor [v3]

[Tobias Holenstein]

> In the Filter window of the IdealGraphVisualizer (IGV) the user can double-click on a filter to edit the javascript code. 
> 
> - Previously, the code window was not resizable and had no syntax highlighting
> <img width="782" alt="editor_old" src="https://user-images.githubusercontent.com/71546117/222137737-1042b272-2c4f-4ae2-929d-2c5d285818e4.png">
> 
> - Now, the code window can be resized by the user and has basic syntax highlighting for `keywords`, `strings` and `comments`
> <img width="727" alt="editor_new" src="https://user-images.githubusercontent.com/71546117/222137687-892ba36d-4a76-4769-ada7-7982ea59a5ac.png">

Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:

  make NetBeans form editor work again

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12803/files
  - new: https://git.openjdk.org/jdk/pull/12803/files/4b2dd4a5..4f02c553

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12803&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12803&range=01-02

  Stats: 45 lines in 2 files changed: 20 ins; 5 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/12803.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12803/head:pull/12803

PR: https://git.openjdk.org/jdk/pull/12803