Powershell: backslash filepath

[rsteube]

Request

Powershell on Windows supports the backslash (\) filepath separator.
This is rather unique as other shells use slash (/).

Since Powershell also supports slash, so so far the decision was made to only support this.
Adding backslash increases complexitiy and poses some issues with prefix filtering.

Seems a mixture of slash and backslash might be possible so support for it might be added at some point.

Proposed solution

Keep the current prefix and continue with / (even if it is mixed).

Anything else?

related carapace-sh/carapace-bin#2035