fix: make nui.nvim optional dependency

[pedro757]

Used new vim.ui.select and vim.ui.input of the neovim api

[vuki656]

Please check out this comment.

I'm down with getting this implemented.

How I'd like it to be done is to make a new file for each UI element and use it from there.

For example, make a file for Select. And then in that file, you would check if the user has Nui, and if it does use Nui if not use the native UI. Then when the Select component is used in the plugin, it doesn't know what UI it uses, it just knows that a Select is used.

[vuki656]

Hey @pedro757, do you still plan on finishing this?