RFR: 8265440: IGV: make node selection more visible

[Koichi Sakata]

This pull request makes node selection more visible.

At present when selecting node, node name is bolder. In addition to that, thickness of the border is bolder after applying this code.

I tested manually. Here are the images that I took before and after applying this patch as follows.

### After Applying the Code
<img width="300" alt="スクリーンショット 2021-06-02 14 40 28" src="https://user-images.githubusercontent.com/60008/120432008-425f3f00-c3b4-11eb-91ed-2f940279affd.png"><img width="300" alt="スクリーンショット 2021-06-02 14 40 43" src="https://user-images.githubusercontent.com/60008/120432019-44c19900-c3b4-11eb-81ad-9412869e1c28.png">

Left: "0 Root" and "3 Start" are selected.
Right: "0 Root" and "3 Start" are selected. "3 Start" and "7 Parm" are highlighted.

<img width="200" alt="スクリーンショット 2021-06-02 14 44 04" src="https://user-images.githubusercontent.com/60008/120432028-468b5c80-c3b4-11eb-8673-9172761a15b2.png"><img width="200" alt="スクリーンショット 2021-06-02 14 44 11" src="https://user-images.githubusercontent.com/60008/120432029-4723f300-c3b4-11eb-833e-f6cb8dd30129.png">

Left: The upper right slot of "20 MergeMem" are selected.
Right: The upper right slot of "20 MergeMem" are selected and highlighted.

### Before Applying the Code
<img width="300" alt="スクリーンショット 2021-06-02 14 41 55" src="https://user-images.githubusercontent.com/60008/120432024-45f2c600-c3b4-11eb-879d-7977caaa0e39.png"><img width="300" alt="スクリーンショット 2021-06-02 14 42 29" src="https://user-images.githubusercontent.com/60008/120432025-45f2c600-c3b4-11eb-85ed-6dd8a0c8ff60.png">

Left: "0 Root" and "3 Start" are selected.
Right: "0 Root" and "3 Start" are selected. "3 Start" and "7 Parm" are highlighted.

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

Commit messages:
 - Update the copyright
 - Make thickness of the border bolder

Changes: https://git.openjdk.java.net/jdk/pull/4298/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4298&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265440
  Stats: 8 lines in 2 files changed: 6 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4298.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4298/head:pull/4298

PR: https://git.openjdk.java.net/jdk/pull/4298