RFR: JDK-8290469: Add new positioning options to PassFailJFrame test framework [v12]

[Harshitha Onkar]

> Additional position setting (TOP_LEFT_CORNER) and a method to obtain bounds of test instruction frame are added to PassFailJFrame to handle positioning of multiple test frames.
> 
> In scenarios where multiple test windows might be present, the test windows might overlap the instruction frame. In order to fix this TOP_LEFT_CORNER position option is added that positions the test instruction frame at top left corner with main test window below it.
> 
> Additionally `getInstructionFrameBounds()` is added to obtain the position and dimensions of test instruction frame.

Harshitha Onkar has updated the pull request incrementally with two additional commits since the last revision:

 - Updated javadoc as per the review comments
   
   Co-authored-by: Alexey Ivanov <70774172+aivanov-jdk at users.noreply.github.com>
 - Updated javadoc as per the review comments
   
   Co-authored-by: Alexey Ivanov <70774172+aivanov-jdk at users.noreply.github.com>

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Changes:
  - all: https://git.openjdk.org/jdk/pull/9525/files
  - new: https://git.openjdk.org/jdk/pull/9525/files/2c72bc35..3a52e6d9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9525&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9525&range=10-11

  Stats: 6 lines in 1 file changed: 1 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/9525.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9525/head:pull/9525

PR: https://git.openjdk.org/jdk/pull/9525