Add a /buff all function

[MartinAskestad]

This will add a /buff all function to complement the /tab all feature for us who primarily uses buffers instead of tabs.

fixes #42

[dtcrusher]

after testing I found one issue where it includes as well other buffers from NERDTree plugin and vim itself and unless i delete these it prevents me from submitting.

// output

#file: NERD_tree_tab_1
#file: VS.Vim.Buffer: 1: VS.Vim.Buffer.Default

// error messages

Error detected while processing function copilot_chat#SubmitMessage[69]..copilot_chat#api#AsyncRequest:
line 8:
E484: Can't open file VS.Vim.Buffer: 1: VS.Vim.Buffer.Default

[MartinAskestad]

Aha! I'm not using nerd tree so I hadn't anticipated that. I'll look into adding a filter to only pick file-buffers.

[MartinAskestad]

I've added a filter to only add listed buffers. Nerdtree, netrw and other plugins set their buffers to unlisted so it should fix the problem.

[dtcrusher]

it works, no other buffers spotted in the wild. thanks!

[Konfekt]

How about /win all to go full circle. As tabs are meant to display multiple windows, /tab all likely only adds the currently active one in each tab?