Disallow dispatch calls with dimensions of zero-length

[ryco117]

1. This is meant to address Using dispatch with dimension 0 along any axis triggers a kernel crash, or freezes the OS #1219 by adding an additional check to check_dispatch() for a zero-length dimension

2. Please put changelog entries in the description of this Pull Request
   if knowledge of this change could be valuable to users. No need to put the
   entries to the changelog directly, they will be transferred to the changelog
   files(CHANGELOG_VULKANO.md and CHANGELOG_VK_SYS.md)
   by maintainers right after the Pull Request merge.

   • Entries for Vulkano changelog:
     • Added new enum value CheckDispatchError::ZeroLengthDimensions to be returned when dispatch() is called with dimension(s) of length zero.

3. Run cargo fmt on the changes.

4. Make sure that the changes are covered by unit-tests.

5. Update documentation to reflect any user-facing changes - in this repository.

Let me know if there are any concerns! (and yes, this issue is pretty low-hanging fruit :P )

[Rua]

Seems like a simple enough fix, thanks!