Add disk stat functions

[li1]

This PR exposes the uv_fs_statfs() libuv 1.31 function to obtain available, used, and total disk.

It closes #37038.

[NHDaly]

Cool, lgtm other than the requests in my comments! :) Thanks for the PR

[li1]

Should I also export the DiskStats and StatFS structs in exports.jl?

[fredrikekre]

An alternative interface could be to have a single function, e.g. diskstat, that returns a struct with documented fields, just like the stat function does for files already.

[Sacha0]

(Requested re-review from Fredrik regarding the interface changes, i.e. addition of diskstat alongside the disk_ functions, where I think his intent might've been to supplant the disk_ functions with the single diskstat export. To be clear, I have no opinion :).)

[li1]

Sorry it took me so long to get back to this, PTAL!

[li1]

Not sure what the remaining test failures are about, any help would be much appreciated!

[Sacha0]

From a brief look at some of the failure logs and associated buildbot histories, at least some of the failures appear likely to be unrelated (noting strings of failures on corresponding buildbots having started before the most recent builds associated with this pull request).

[Sacha0]

To confirm, there appear to be ongoing CI issues; hopefully those will be resolved in the not too distant future, then this pull request can be rebased, and we can have another look :).

[Sacha0]

I am not certain whether the unrelated failures that show up in some of these logs have been resolved, but folks have been working on them and most recent builds appear to be passing. Perhaps rebase / clean up the history a bit and push to get another snapshot? :)

[vtjnash]

A few fixes and suggestions for you. Looks pretty good so far. The CI failures look mostly familiar from some issues last week.

[li1]

Sorry again for the slow progress on this PR — I've removed StatFS and instead specialized getproperty. I'm not completely happy with the Base.show overload yet — it seems a little brittle. Also e.g.

x = diskstat()
?x

won't print out the "virtual" fields total, available, used, but I don't really want to copy over the summarize code from docview.jl just to inject those fields. Maybe there's a more elegant Julian way that I'm missing?

[vtjnash]

Can you add a line to the NEWS.md file and another line to the doc/src/base/file.md file? The rest LGTM!

[li1]

Thanks again for all the reviews, much appreciated! Added your feedback and updated the docs + NEWS.

[vtjnash]

Thanks so much for sticking with this PR. I've put the merge-me tag on, so that we either merge it soon, or there is one last chance for anyone to comment.

[NHDaly]

++ not bad for a first contribution! :) Thanks for the PR!