This implements the delete operator in curves edit mode. The behavior
is similar to the delete operator in the edit mode of legacy curves,
i.e. it's actually dissolving and doesn't split curves. This is also
the behavior that we generally want for the hair use case.
The operator is added to the `Curves` menu and can be accessed via
the keyboard using `X` or `Del`.
Pull Request #104765
3807a0981e