RFR: 8267551: Support loading images from inline data-URIs [v13]

[Michael Strauß]

> This PR adds support for loading images from [inline data URIs](https://en.wikipedia.org/wiki/Data_URI_scheme), which is also widely supported by web browsers. This enables developers to package small images in CSS files, rather than separately deploying the images alongside the CSS file.

Michael Strauß has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:

 - Merge branch 'master' into feature/image-datauri
   
   # Conflicts:
   #	modules/javafx.graphics/src/test/java/test/com/sun/javafx/iio/ImageStorageTest.java
 - Accept regular file paths, change javadoc
 - Merge branch 'openjdk:master' into feature/image-datauri
 - Rename DataURI.isValidURI
 - Reverted a change
 - Allow leading and trailing whitespace in data URI
 - Removed test
 - Changed data URI detection
 - Merge branch 'master' into feature/image-datauri
 - Moved test
 - ... and 5 more: https://git.openjdk.java.net/jfx/compare/7b7050c4...315523c5

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Changes: https://git.openjdk.java.net/jfx/pull/508/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=508&range=12
  Stats: 566 lines in 8 files changed: 501 ins; 23 del; 42 mod
  Patch: https://git.openjdk.java.net/jfx/pull/508.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/508/head:pull/508

PR: https://git.openjdk.java.net/jfx/pull/508