Use newly-supported KVector Unitful extension to simplify differential

[mikeingold]

Status

Need to rebase after completion of #122.

Changes

• Increases minimum compat version of CliffordNumbers.jl dependency to v0.1.9
• Uses CliffordNumbers.jl's new Unitful extension, converting Meshes.Vec to Unitful.Quantity{KVector} which now support unit-aware wedge products
• Add a new utility method _units(::Meshes.Vec)

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	_units(::Meshes.Geometry{M, CRS}) where {M, CRS} = Unitful.unit(CoordRefSystems.lentype(CRS))
	function _units(::Meshes.Geometry{M, CRS}) where {M, CRS}
	Unitful.unit(CoordRefSystems.lentype(CRS))
	end

[brainandforce]

Just realized that you're depending on me for this PR, so I'll push 0.1.9 out for your convenience.

[mikeingold]

Just realized that you're depending on me for this PR, so I'll push 0.1.9 out for your convenience.

Thanks! This one is in line behind a much heftier PR, so no worries on the release timing.

To your credit, CliffordNumbers.jl turns one of our core functions into a borderline one-liner, which is much more elegant than the previous solution. 😄

[mikeingold]

I had trouble getting git merge to run successfully after the huge #122 merge, so I'm closing this in favor of a new branch PR in #130.