RFR: JDK-8305885: Use ReadOnly*PropertyBase class where possible [v2]

[John Hendrikx]

> These changes use base classes for custom properties where possible for the `ExpressionHelper` logic (and in one case, all the bind logic as well) instead of duplicating these each time. As the base classes receive far more scrutiny, this should reduce bugs in these re-implementations.

John Hendrikx 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:

  Use property base classes where possible

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1092/files
  - new: https://git.openjdk.org/jfx/pull/1092/files/506b86e9..eda5d621

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1092&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1092&range=00-01

  Stats: 133 lines in 1 file changed: 71 ins; 27 del; 35 mod
  Patch: https://git.openjdk.org/jfx/pull/1092.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1092/head:pull/1092

PR: https://git.openjdk.org/jfx/pull/1092