RFR: 8245284: Update to 610.1 version of WebKit

[Arun Joseph]

Update JavaFX WebKit to GTK WebKit 2.28 (610.1)

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Commit messages:
 - Fix exec files
 - 8245284: Update to 610.1 version of WebKit

Changes: https://git.openjdk.java.net/jfx/pull/263/files
 Webrev: https://webrevs.openjdk.java.net/jfx/263/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8245284
  Stats: 301003 lines in 5370 files changed: 146627 ins; 94168 del; 60208 mod
  Patch: https://git.openjdk.java.net/jfx/pull/263.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/263/head:pull/263

PR: https://git.openjdk.java.net/jfx/pull/263