Feature request: Allow building from source

[billdenney]

I was recently hit this issue: https://community.rstudio.com/t/error-in-initializeptr-function-cholmod-factor-ldeta-not-provided-by-package-matrix/178694

Briefly, the Matrix package was no longer binary-compatible from older to newer versions after an R and package upgrade. I think that there was a sequencing issue in my updates where I updated many packages and then I updated Matrix after that. In the end, I'm not sure if this was a pak issue or a more general issue for the order that I did things.

But, I wanted to use pak to rebuild everything from source and reinstall them, but I didn't see a way to require source rebuild (the equivalent of using install.packages(..., type = "source")). For this use case, I think it would be useful to be able to rebuild from source.

[gaborcsardi]

See here: https://pak.r-lib.org/reference/faq.html#how-do-i-install-a-package-from-source-

[billdenney]

Would you consider a PR that puts that info into ?pkg_install?