This adds isNullOrEmpty string helper that cheks if string is... well
null or empty. It is done to improve readability of the code and better
express intent.
This commit is generated using regex based find and replace:
```
s/[\w:]+_cast\s*<([^>]+)\*>\s*\(\s*getObject\(\s*\)\)/getObject<$1>/
s/[\w:]+_cast\s*<([^>]+)\*>\s*\(\s*([^)]*)\s*->\s*getObject\(\s*\)\)/$2->getObject<$1>()/
```
To regenerate if needed.
* Update Sketcher toolbar UIs.
Group all create tools for arcs, conics.
Group toggle driving/active constraints.
Update arrangement of icons.
* Change default to unified coincidence tool.
The edit datum dialog is opened by double-clicking on a dimensional constraint in a sketch. However, the double-clicking event doesn't work realiably on
some systems. As a workaround this PR adds the command to the context-menu.
For more details see the forum thread: https://forum.freecad.org/viewtopic.php?t=71137
The following commits were squashed into this
[Sketcher] Handle some corner cases in AngleViaPoint
[Sketcher] Avoid redundant constraints with B-splines...
When involving tangent, perpendicular and angle constraints.
[Sketcher] Add pre-commit changes
[Sketcher] Do not allow 2-selection tangent with B-spline
Also...
[Sketcher] Report error when using direct tangency with B-splines
[Sketcher] Fix malformed constraint when B-spline is selected second
To clarify, this means the second curve selected. The position of the point in
selection order does not matter in angle-via-point.
[Sketcher] Fix wrong number for B-Spline tangent on redundancy
[Sketcher] Remove existing point-on-object in some redundant cases
Particularly when point constrained on a B-spline is being used for
tangent, perpendicular or angle via point with the same B-spline.
[Sketcher] Fix direction issue with B-spline tangents.
Without these changes the solver might try to "twist" the B-spline to make the
angle between curves be 0 instead of PI (which may be closer to the initial shape).
This is fix to issue mentioned in the #11717, on discord and forum that
for smart dimension tool the chosen tool should not be remembered. This
will ensure that the "smart" tool is always visible on the toolbar and
other tools are accessible in case that such explicit choice is needed.
