RFR: 8360498: [TEST_BUG] Some Mixing test continue to fail

[Khalid Boulanouare]

This PR will consolidate fixes of the following bugs:

https://bugs.openjdk.org/browse/JDK-8361188
https://bugs.openjdk.org/browse/JDK-8361189
https://bugs.openjdk.org/browse/JDK-8361190
https://bugs.openjdk.org/browse/JDK-8361191
https://bugs.openjdk.org/browse/JDK-8361192
https://bugs.openjdk.org/browse/JDK-8361193
https://bugs.openjdk.org/browse/JDK-8361195

This PR depends on https://github.com/openjdk/jdk/pull/25971

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Depends on: https://git.openjdk.org/jdk/pull/25971

Commit messages:
 - Checks if component is null for pixel color verification
 - Removes test from Problem List
 - Returns false if component is null, in the case of embedded frame

Changes: https://git.openjdk.org/jdk/pull/26625/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26625&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360498
  Stats: 5 lines in 2 files changed: 2 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/26625.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26625/head:pull/26625

PR: https://git.openjdk.org/jdk/pull/26625