fix(lualine): pretty path fix for mixed case paths on Windows (#4911)

## Description

Here's an example of the issue:

```lua
local pretty_path = require('lazyvim.util').lualine.pretty_path({ relative = 'cwd' })

-- just a stub
local component = {
  create_hl = function() end,
  format_hl = function() return '' end,
  get_default_hl = function() return '' end
}

local cwd = vim.fn.getcwd()
vim.print('cwd: ' .. cwd)
vim.print('pretty path: ' .. pretty_path(component))

-- results if `cd d:\tmp` was called previously
-- cwd: d:\tmp
-- pretty path: d:\tmp\pretty_path_issue.lua
--
-- results if `cd D:\tmp` was called previously
-- cwd: D:\tmp
-- pretty path: pretty_path_issue.lua
```

Depending on the initial path of the `cd` we either get a pretty path or
we don't =)

I'm not sure if this should be fixed in the neovim itself (considering
windows paths as case-insensitive), but I would assume that would take a
lot longer to land there, if it's even considered a needed change

## Related Issue(s)

Somewhat related to #4763, where I've left a comment, but decided to
look a bit deeper

## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/util/lualine.lua

@@ -101,9 +101,20 @@ function M.pretty_path(opts)
     local root = LazyVim.root.get({ normalize = true })
     local cwd = LazyVim.root.cwd()
 
-    if opts.relative == "cwd" and path:find(cwd, 1, true) == 1 then
+    -- original path is preserved to provide user with expected result of pretty_path, not a normalized one,
+    -- which might be confusing
+    local norm_path = path
+
+    if LazyVim.is_win() then
+      -- in case any of the provided paths involved mixed case, an additional normalization step for windows
+      norm_path = norm_path:lower()
+      root = root:lower()
+      cwd = cwd:lower()
+    end
+
+    if opts.relative == "cwd" and norm_path:find(cwd, 1, true) == 1 then
       path = path:sub(#cwd + 2)
-    elseif path:find(root, 1, true) == 1 then
+    elseif norm_path:find(root, 1, true) == 1 then
       path = path:sub(#root + 2)
     end