RFR: 8150564: Migrate useful ExtendedRobot methods into awt.Robot [v8]

[Alisen Chung]

> Some useful methods in ExtendedRobot should be migrated into Robot itself so that ExtendedRobot can be removed in the future. The tests using ExtendedRobot for these migrated methods are changed to use only Robot (removing unnecessary building of ExtendedRobot).

Alisen Chung has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 14 commits:

 - Merge branch 'master' of https://github.com/openjdk/jdk into 8150564
 - update specification to public default fields, add waitforidle exceptions to specifications
 - add specification to public default fields
 - fix var names in ER
 - update specifications
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8150564
 - merge
 - move mouseMove back to ER
 - extendedRobot
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8150564
 - ... and 4 more: https://git.openjdk.org/jdk/compare/16232578...a8482f56

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Changes: https://git.openjdk.org/jdk/pull/22044/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22044&range=07
  Stats: 861 lines in 236 files changed: 257 ins; 430 del; 174 mod
  Patch: https://git.openjdk.org/jdk/pull/22044.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22044/head:pull/22044

PR: https://git.openjdk.org/jdk/pull/22044