Runtime: add arbitrary file upload to working dir in web interface

SVGHMI: fix double-dispatch happening when using low widget update frequency on variable already being updated with high frequency by other widgets.

Merge

Backed out changeset ddadbdf20e70, no effect on current problem.

GH CI: try reverting to previous version of ubuntu

IDE tests: ensure that file browser idled before entering path in new_project

tests/tools: move comment and remove dead code in Dockerfile

tests: add tesseract training data "tessdata", still trying to enhance OCR reliability in UI tests

tests: attemps to make OCR based hits more stable

Tests: fix path logic in Docker creation script, consequence of previous commit.

Tests: cleanup and tidy docker definitions and scripts

Merged changes from default in wxPython4 branch

SVGHMI: fix XY graph init (consequence of earlier change) + reindent

Earlier change did modify the variables attributes (options) are stored in widget objects. XY graph uses variables' min and max to determine range.

SVGHMI: move declaration of "xmlns" javascript const so that widgets can use it.

This was broken in earlier commit, when changing initial execution order because of implementing websocket reconnect.