RFR: 8278924: [Linux] Robot key test can fail if multiple keyboard layouts are installed [v2]

[Martin Fox]

> The Robot implementation on Linux did not consult the current layout when mapping from a KeyCode to a hardware code. Internally it retrieved results for all the layouts but just picked the first one it saw leading to random effects. Though not part of the original bug report, the code also ignored the shift level when choosing which result to pick. On a French layout the dollar sign is on two keys (AltGr 4 is the second one) and the code could choose either one. Same is true for pound.
> 
> This PR consults the current layout and only on shift level 0 which is the same level used in get_glass_key to figure out which KeyCode to assign when generating a KeyEvent.

Martin Fox has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge remote-tracking branch 'upstream/master' into linuxrobot
 - Robot no longer gets confused by multiple layouts

-------------

Changes:
  - all: https://git.openjdk.org/jfx/pull/718/files
  - new: https://git.openjdk.org/jfx/pull/718/files/ad88f044..51fcd047

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=718&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=718&range=00-01

  Stats: 1319402 lines in 14954 files changed: 713165 ins; 422282 del; 183955 mod
  Patch: https://git.openjdk.org/jfx/pull/718.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/718/head:pull/718

PR: https://git.openjdk.org/jfx/pull/718