SVGHMI: update generated XSLT

SVGHMI: stuff test so that it moves all the time, to have better chance to spot memory leaks...

SVGHMI: prevent unwnted context menu and pinch zoom

SVGHMI: more attempts to prevent losing memory in JS closure

SVGHMI: WIP trying to reduce memory usage : use .onclick onstead of SetAttribute, avoid useless closure and object creation when possible, etc.

SVGHMI: update generated xslt file

SVGHMI: use const when applicable

SVGHMI: prevents text and svg elements selection on the whole page when dragging.

SVGHMI: Update default test to check that Input widget is indeed updated when variable changes.

SVGHMI: Fix: on screen keyboard wasn't showing up when editing local variables through Input widget.

Project tree: avoid flickering and glitches in notebook when selecting some still not opened ConfigTreeNode

merge

py_ext: better handling of coma separated OnChange attribute for python safe global variables.

Project tree: Clicking on ConfigTreeNode should have same behaviour as for POUS and other IEC types : simple click to select and double click to open.

Allow customization of generated py_ext OnChange calls, by adding a static method to PythonFileCTNMixin that can the be later hot patched.