New SVG icons, `Sketcher_DeleteConstraints`, `Sketcher_DeleteGeometry`
for two commands which previously used the very simple icon
`Element_SelectionTypeInvalid` (a single red X).
These icons clarify that the commands are used to delete
the constraints and the geometry, respectively.
Most tools should be exposed in the toolbars and not kept
"hidden" in the menus.
* `ConstrainInternalAlignment` is added in the "constraints" toolbar.
* `SelectElementsWithDoF` is added in the "tools" toolbar.
Also amend the name of the `Sketcher_BSplineConvertToNURB` command.
`SelectConstraints`, `SelectElementsAssociatedWithConstraints`,
these include the icon for parallel constraint, which was upgraded
in ed8ba392.
`SelectRedundantConstraints`, `SelectConflinctingConstraints`,
previosuly were the same with only a small color variation (orange
outline and red outline). Now they have another symbol overlayed
(lightning and exclamation mark) to distinguish them more clearly.
The parallel icon was also upgraded in these icons.
The `Move` icon is also made more clear. The first element
now has a clear outline, instead of being a faded green color
which is hard to see. An arrow is added to imply movement
from the first position to the second position.
`Sketcher_ConstrainBlock` to `Constraint_Block`.
`Sketcher_ConstrainLock` to `Constraint_Lock`, and the corresponding
`_Driven` variant.
Adjust the icons in the taskpanel for the sketcher constraints,
elements, and for the action menu for constraints.
Adjust the icon order in the `Sketcher.qrc` resource file.
An empty block after a conditional can be a sign of an omission and can decrease maintainability of the code.
Such blocks should contain an explanatory comment to aid future maintainers.