RFR: WIP: 8260528: Clean glass-gtk sizing and positioning code [v7]

[Thiago Milczarek Sayao]

> This cleans size and positioning code, reducing special cases, code complexity and size.
> 
> Changes:
> 
> - cached extents: 28, 1, 1, 1 are old defaults - modern gnome uses different sizes. It does not assume any size because it varies - it does cache because it's unlikely to vary on the same system - but if it does occur, it will only waste a resize event.
> - frame extents are received in process_property_notify;
> - window geometry, min/max size are centralized in update_window_constraints and uses  `XSetWMNormalHints` because it supports initial position;
> - window_configure: Changes can be requested directly to the window manager with `XReconfigureWMWindow` - it's compatible with `windowChangesMask`, `windowChanges`;
> - request_focus uses `_NET_ACTIVE_WINDOW` directly as it does not seem to have focus stealing problems.
> 
> I have left some debug print statements which will be removed when we finish testing.

Thiago Milczarek Sayao has updated the pull request incrementally with one additional commit since the last revision:

  Fix initial size

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/915/files
  - new: https://git.openjdk.org/jfx/pull/915/files/0be4fca9..e8bfec02

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=915&range=06
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=915&range=05-06

  Stats: 65 lines in 2 files changed: 42 ins; 14 del; 9 mod
  Patch: https://git.openjdk.org/jfx/pull/915.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/915/head:pull/915

PR: https://git.openjdk.org/jfx/pull/915