fix(__internal) : fix slash problem in oldfiles

[Jaehaks]

Description

• Problems

Problem with slash and backslash being mixed up is chronic issue of neovim in Windows. it makes telescope prompt perceive same path differently when it execute to oldfiles picker.

some function like nvim_buf_get_name() or vim.v.oldfiles give paths which are mixed up with slash and backslash.

• What it did For windows,

it always needs to change slash(/) to backslash() when function which deal with path because entry_maker works properly only the case that path string has \ not /.

• Effect

1. oldfiles picker doesn't show duplicated list
2. defaults.path_display configuration feature will works well at oldfiles pikcer

Fixes #1683
It is related with PR #3103 what i submitted but opened

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list relevant details about your configuration

• [ v ] Test A

1. open oldfiles picker
2. path_display feature will works all entry of oldfiles.
   (before the issue is fixed, the path which has slash and backslash being mixed up cannot be applied by path_display
   even though vim.opt.shellslash is true
   

I checked with formatter stylua also and add some simple comment about it

Configuration:

• Neovim version (nvim --version): v0.10.0
• Operating system and version: Windows 10

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)

[jamestrew]

Sorry is this the same fix as #3103
Looks largely the same to me.

[Jaehaks]

@jamestrew
Ok, I agree that the modification of plenary.nvim is fundamental solution.
I hope your PR is accepted :)

[jamestrew]

Sorry I must've confused you with a comment I deleted about plenary.
I think this PR could still be helpful since this code path is dealing with file paths before plenary even comes into play.

I just wanted to confirm that this fixes the same issue as #3103 -- seems like a simpler fix so I'd probably prefer this PR over #3103 if that's alright.

I would probably just ask to remove all but the first -- for slash problem in windows comment.

[Jaehaks]

@jamestrew

Ok, New commit is uploaded with erased comments except of first one.
This PR is same with #3103, just I modified more precise because I don't know how to upload new commit before.

[jamestrew]

Thanks!