RFR: 8150564: Migrate useful ExtendedRobot methods into awt.Robot [v15]

[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 22 commits:

 - merge
 - update specifications, replace default values in specifications with links to default var
 - update glide in test
 - merge
 - fix test with removed robot.glide using points
 - add code tag to specifications in Robot
 - fix syncdelay in ER
 - removing lesser used overridden methods
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8150564
 - update specification to public default fields, add waitforidle exceptions to specifications
 - ... and 12 more: https://git.openjdk.org/jdk/compare/10791477...30ca6a6b

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Changes: https://git.openjdk.org/jdk/pull/22044/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22044&range=14
  Stats: 818 lines in 236 files changed: 205 ins; 433 del; 180 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