Backport this a11y fix to jfx17u. This is not a clean backport. The source code changes apply cleanly but there was a conflict in test file. The test `DialogTest.java` file does not exist in jfx17u source. The file is now added but only with one test that was added as part of this fix to mainline, and other pre-existing tests are removed. Tested that fix works as expected on Windows and macOS
------------- Commit messages: - remove unused import - 8087557: [Win] [Accessibility, Dialogs] Alert Dialog content is not fully read by Screen Reader Changes: https://git.openjdk.org/jfx17u/pull/91/files Webrev: https://webrevs.openjdk.org/?repo=jfx17u&pr=91&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8087557 Stats: 89 lines in 6 files changed: 88 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jfx17u/pull/91.diff Fetch: git fetch https://git.openjdk.org/jfx17u pull/91/head:pull/91 PR: https://git.openjdk.org/jfx17u/pull/91
