feat(keymaps): dynamic which-key icons/descriptions for toggles (#4050)

## Description

<!-- Describe the big picture of your changes to communicate to the
maintainers
  why we should accept this pull request. -->

## Related Issue(s)

- [ ] Closes #4025

## Screenshots


![image](https://github.com/user-attachments/assets/8453c23c-d560-490c-9f96-a22ea88f45fd)

## Checklist

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

lua/lazyvim/plugins/editor.lua

@@ -176,9 +176,9 @@ return {
           { "<leader>gh", group = "hunks" },
           { "<leader>q", group = "quit/session" },
           { "<leader>s", group = "search" },
-          { "<leader>u", group = "ui" },
+          { "<leader>u", group = "ui", icon = { icon = "󰙵 ", color = "cyan" } },
           { "<leader>w", group = "windows" },
-          { "<leader>x", group = "diagnostics/quickfix" },
+          { "<leader>x", group = "diagnostics/quickfix", icon = { icon = "󱖫 ", color = "green" } },
           { "[", group = "prev" },
           { "]", group = "next" },
           { "g", group = "goto" },
@@ -193,7 +193,7 @@ return {
         function()
           require("which-key").show({ global = false })
         end,
-        desc = "Buffer Local Keymaps (which-key)",
+        desc = "Buffer Keymaps (which-key)",
       },
     },
     config = function(_, opts)