Currently broken for Windows with MSYS2

[tasop-rsconnect]

Installing a version of node (specifically 10.23.2) has the following problems:

• OS detection doesn't work.
  This is because nvm.fish line 42 uses string lower, but line 52 compares to uppercase strings.
• Solving the above, curl (line 81) fails with curl: (23) Failure writing output to destination
  I worked around that by having curl save to a temp file, and then tar read from that file.
• Working around the above, the tar part of installing (line 82) fails for some reason I couldn't determine.
  It works if I separate it into two commands instead of using && or ; and in lines 81-82.
• Working around the above, _nvm_node_info fails because apparently npm is directly inside version/bin instead of node_modules/npm, so package.json isn't in the same directory.

Using it on Windows 10 with MSYS2.
curl version: 7.74.0 (x86_64-pc-msys)
tar version: bsdtar 3.3.2 - libarchive 3.3.2 zlib/1.2.5.f-ipp

I decided against making a pull request since I only have workarounds for the above and I can't be sure it would work in general, but I can hope this information helps you figure out the problems.

[M4RC3L05]

@tasop-rsconnect I had the same issues you describe, so i made a fork with patches for msys2/mingw here, maybe this can help.

@jorgebucaran If this is a good solution i'm happy to make a PR.

[jorgebucaran]

I'd love a PR! @M4RC3L05

[matteopt]

@jorgebucaran
I've created a new pull request to fix this, it uses either unzip or bsdtar (included in MSYS2).
#192