RFR: WIP: 8260528: Clean glass-gtk sizing and positioning code [v21]

[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.
> - window geometry, min/max size are centralized in update_window_constraints;
> - Frame extents (the window decoration size used for "total window size":
>     - frame extents are received in process_property_notify;
>     - removed quirks in java code;
>     - When received, call set_bounds again to adjust the size;
> - Removed `activate_window` because it's the same as focusing the window. `gtk_window_present` will deiconify and focus it.
> - `requested_bounds` removed - not necessary;
> - `window_configure` incorporated in set_bounds with `gtk_window_move` and `gtk_window_resize`;
> - `process_net_wm_property` is a work-around for Unity only.

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

  Back to gtk_window_set_focus_on_map FALSE to avoid the WM to tamper with window order

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/915/files
  - new: https://git.openjdk.org/jfx/pull/915/files/6e63bb52..f7d93814

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=915&range=20
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=915&range=19-20

  Stats: 7 lines in 1 file changed: 3 ins; 0 del; 4 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