RFR: JDK-8293776 : Adds CSS 4 and 8 digits hex coded Color

[ScientificWare]

This is referenced in Java Bug Database as
- [JDK-8293776 : Adds CSS 4 and 8 digits hex coded Color](https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8293776)

This is tracked in JBS as 
- [JDK-8293776 : Adds CSS 4 and 8 digits hex coded Color](https://bugs.openjdk.java.net/browse/JDK-8293776)

Adds the 4 and 8 digits color hex notations to CSS.java, as described in :
CSS Color Module Level 4
W3C Candidate Recommendation Snapshot, 5 July 2022
[6.2 The RGB Hexadecimal Notations: `#RRGGBB`](https://www.w3.org/TR/css-color-4/#hex-notation)

Designed from : [ScientificWare JDK-8293776 : Adds CSS 4 and 8 digits hex coded Color](https://github.com/scientificware/jdk/issues/13)

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Commit messages:
 - Adds final modifier.
 - Adds or removes spaces.
 - Removes int cast.
 - Update Copyrigth.
 - Remove NumberFormatException
 - Adds missing import and declaration.
 - Typo.
 - Adds new color hex formats.

Changes: https://git.openjdk.org/jdk/pull/10317/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10317&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293776
  Stats: 49 lines in 1 file changed: 28 ins; 3 del; 18 mod
  Patch: https://git.openjdk.org/jdk/pull/10317.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10317/head:pull/10317

PR: https://git.openjdk.org/jdk/pull/10317