RFR: JDK-8298528: Clean up raw type warnings in base in bindings and collections packages

[John Hendrikx]

Packages fixed:
- com.sun.javafx.binding
- com.sun.javafx.collections
- javafx.beans
- javafx.beans.binding
- javafx.collections
- javafx.collections.transformation

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Commit messages:
 - Use static method for no-op map
 - Fix raw type warnings in base

Changes: https://git.openjdk.org/jfx/pull/972/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=972&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298528
  Stats: 334 lines in 23 files changed: 81 ins; 75 del; 178 mod
  Patch: https://git.openjdk.org/jfx/pull/972.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/972/head:pull/972

PR: https://git.openjdk.org/jfx/pull/972