RFR: 8196065: ListChangeListener getRemoved() returns items that were not removed. [v2]

[mstr2]

> The documentation for `ObservableListBase.nextRemove` states that a single change always refers to the current state of the list, which likely means that multiple disjoint removed ranges need to be applied in order, otherwise the next change's `getFrom` doesn't refer to the correct index.
> 
> `SelectedItemsReadOnlyObservableList` doesn't apply removals to `itemsRefList`, which means that subsequent removals will refer to the wrong index when retrieving the removed elements. This PR fixes the calculation of the current index.

mstr2 has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  Fix incorrect index when multiple remove changes are handled in SelectedItemsReadOnlyObservableList

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Changes:
  - all: https://git.openjdk.java.net/jfx/pull/478/files
  - new: https://git.openjdk.java.net/jfx/pull/478/files/11259335..aafa0e9c

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=478&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=478&range=00-01

  Stats: 9 lines in 2 files changed: 3 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jfx/pull/478.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/478/head:pull/478

PR: https://git.openjdk.java.net/jfx/pull/478