Isaac Wheeler

@gustaphe should probably weigh in on this, I suspect

> I am generally in favor, have not checked the details yet. I can't even run the code, something about `key :pgfplotsx not found` on line 240 of UnitfulExt, but...

With the most recent commit, this implements the more "elegant" solution of waiting until render time to generate the guide, at which point unit and unit format are both known....

I believe all the tests are passing now. To make that so, I had to do a couple things that may merit discussion. - Move `ProtectedString` into `PlotsBase`, rather than...

> @Ickaser,do you think this PR is ready ? Is it fixing #5093 or not ? tldr; The bulk of the changes are here and decisions are made, but there...

I actually hadn't yet put a couple of the last changes from #5098 into this PR 😅 that probably wasn't obvious though (commits https://github.com/JuliaPlots/Plots.jl/pull/5098/commits/21ecaadec4528e1f33031745f11d6f6dad7183ff, https://github.com/JuliaPlots/Plots.jl/pull/5098/commits/0f88e9edf8ff8d2c2ef94f44ddcfd257f126d3fa, https://github.com/JuliaPlots/Plots.jl/pull/5098/commits/7875bc440982e0042e6eba58b03021d96b5a8ab6 ) I can open...

I ran into this today with Unitful and NaNMath. It would be straightforward to add an extension to Unitful that covers `sqrt` and `pow`, but if there is an easy...

This PR isn't quite ready yet, because I think it deserves a few more tests for the UnitfulExt before merging, plus some additions to the docs. But @t-bltg the CI...

Progress: - [x] Tests added and passing - [x] ProtectedString has a `Base.depwarn` - [x] Added to the UnitfulExt docs - [x] Double check that UnitfulExt docs are correct and...

@gustaphe, I realized today that I was assuming the `:none` unitformat should put no unit in the axis label, where the current behavior is more like "no special symbols on...