URI encoding for Windows OS

@timbl @angelo-v
The following PR in 2017 rejects the use of : | / in POST. I suppose it was to preserve the possibility to use NSS on windows.
https://github.com/solid/node-solid-server/commit/5bba6c931fe0b319b6b350b8338b6e144b0b67fa#diff-98a11be785b8100aab3a553eed0e3656a235f06463d2979fd08bafcdf503abdf

      slug = decodeURIComponent(slug)
      if (slug.match(/\/|\||:/)) {
        throw error(400, 'The name of new file POSTed may not contain : | or /')
      }

Using longChat in chat With Me encounters some problem because this control is not applied on PUT, when creating intermediate folders.
see https://github.com/solid/chat-pane/issues/51

I suppose we need some coherence, what is your position :

1. remove the control in POST
2. add the control in all write functions including PUT PATCH (filename and intermediate containers)

Start by reviewing commit 5bba6c931fe0b319b6b350b8338b6e144b0b67fa and the POST, PUT, and PATCH write paths, then compare the longChat failure described in solid/chat-pane#51. Done means the handling of ':', '|', and '/' is coherent for POST, PUT, PATCH, filenames, and intermediate containers, with the chosen behavior documented or covered by the relevant tests.