RFR: 8314820: Unify Screen adapter ordinal logic [v2]

[Marius Hanl]

> This is a small improvement that was noted back in https://github.com/openjdk/jfx/pull/1200#issuecomment-1671954361 by @mstr2, and was on my list since then.
> 
> The idea is to have only one place for assigning `adapter ordinals` – within `Screen`. The corresponding setter `setAdapterOrdinal` can therefore be made private. This improves the separation of responsibilities a little. :-)

Marius Hanl 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 branch 'master' of https://github.com/openjdk/jfx into 8314820-unify-screen-adapter
 - 8314820: Unify Screen adapter ordinal logic

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/2009/files
  - new: https://git.openjdk.org/jfx/pull/2009/files/b49db9a9..112e2920

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=2009&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=2009&range=00-01

  Stats: 1366 lines in 34 files changed: 1189 ins; 89 del; 88 mod
  Patch: https://git.openjdk.org/jfx/pull/2009.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/2009/head:pull/2009

PR: https://git.openjdk.org/jfx/pull/2009