RFR: JDK-8297412: Remove easy warnings in javafx.fxml, javafx.media, javafx.swing, javafx.swt and javafx.web [v3]

[John Hendrikx]

> - Remove unsupported/unnecessary SuppressWarning annotations
> - Remove reduntant type specifications (use diamond operator)
> - Remove unused or duplicate imports
> - Remove unnecessary casts (type is already correct type or can be autoboxed)
> - Remove unnecessary semi-colons (at end of class definitions, or just repeated ones)
> - Remove redundant super interfaces (interface that is already inherited)
> - Remove unused type parameters
> - Remove declared checked exceptions that are never thrown
> - Add missing `@Override` annotations

John Hendrikx has updated the pull request incrementally with one additional commit since the last revision:

  Revert changes to javafx.web src/main/native

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Changes:
  - all: https://git.openjdk.org/jfx/pull/958/files
  - new: https://git.openjdk.org/jfx/pull/958/files/1c5e0fdd..da0439c6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=958&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=958&range=01-02

  Stats: 957 lines in 103 files changed: 4 ins; 919 del; 34 mod
  Patch: https://git.openjdk.org/jfx/pull/958.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/958/head:pull/958

PR: https://git.openjdk.org/jfx/pull/958