Merge default in wxPython4

SVGHMI: fix HMI freeze at load when no screen saver is defined

SVGHMI: update generated XSLT

SVGHMI: watchdog now calls OnStart and OnStop commands just after calling OnWatchdog. Therefore, OnWatchdog command should not restart browser by itself.

SVGHMI: server systematically resets session on connect, rather than waiting for client to ask for it

IDE: Fix DropTarget() methods that must return a bool with wxPython4.

IDE: Fix visibility of text in Debug panel when using dark theme.

IDE: Fix use of deprecated wx.NamedColour

Merged changes from default in wxPython4 branch

SVGHMI: update generated XSLT

SVGHMI: use messy test/projects/svghmi to give a try to ScreenSaver feature.

SVGHMI: cosmetic fix in Back widget

SVGHMI: add ScreenSaver feature. Automatically jumps to a page named "ScreenSaver" after timeout defined in page arguments.

Backed out changeset c6068b674b30

SVGHMI: update generated XSLT

SVGHMI: enable periodical reconnect when browser is QtWebengine, working around memory leak with websocket on Qt's embedded Chromium.

IDE: Added filtering in POU instance variables panel.

SVGHMI: add automatic reconnection of websocket with 1s reconnection delay after first attempt.

SVGHMI: prevent browser and watchdog commands to become zombie once finished.

SVGHMI: svghmi_references exemple: add missing PLC part to demonstrate assigning PLC/HMI variables when validating a modal dialog.

SVGHMI: cosmetic fixes

runtime: remove forgotten printf at starup when retain memory is restored.

OPC-UA client: add ApplicationUri parameter in case it differs from server's URI

Runtime: fix PLC not terminating when being Repaired (i.e purged).

IDE: fix exception when re-opening previously closed tab

IDE: fix SFC Action editor's text not visible on GTK3's dark themes.

IDE: fix action block editor's GridCellEditor. Consequence of wxPython4 bump.

Update README.md

removed undue blank lines

Update README.md

use back quote instead of simple quote for quoted strings.

IDE: fix exception when removing a file in Project Files manager.

Update README.md

Tests: fix OPC-UA test when run from repo.

project_files directory isn't commited because empty,
test fails if project_files is missing.

OPC-UA: better logging in case of failure at init

Tests: version bump open62541 v1.3.2 -> v1.3.3 for github CI workflow.

Tests: add opc-ua encrypted test

Merged changes from default

SVGHMI: update generated XSLT

SVGHMI: Update svghmi_references example to demonstrate use of Assign widget.

SVGHMI: Add Assign widget, doing multiple assignments on click.

SVGHMI: add visible feedback to Jump widget when clicked/touched

SVGHMI: add support for "reference" and "frame" rectangles to spread-out ovelapping elements.

When HMI become complicated, designer needs to spread-out ovelapping elements
in order to unclutter drawing and facilitate maintenance.

SVGHMI: remove intermediate "updates" Map and apply_updates()

It was used initially to decouple DOM updates from reception of data through
websocket, but now since all widget SHOULD use animate() to modify DOM, and
dispatch() only change internal state, apply_update is unnecessary.

SVGHMI: cosmetic fix in js

SVGHMI: do not discard out-of-page elements inside widgets that are ovelapping pages.

SVGHMI: update generated XSLT

OPCUA: cosmetic fixes

CLI: poll runtime log and output new entries to stdout.

CLI: when using --keep, do not disconnect before being interrupted