feat: undojoin timestamp updates

[benlubas]

addresses issues brought up in #1112 (currently closed)

Problem

Updating the time stamp can cause issues with undo-ing things. This is particularly bad when an autosave plugin is used b/c the user will make a change > autosave > timestamp update > autosave > undo (undoes timestamp update) > autosave > timestamp update > loop. The scenario's described assume there is an autosave plugin saving on text change/insert leave.

Making it impossible to undo changes in the norg file with autosave (while the updated: field is present in the metadata).

Proposed Solution

This PR makes two changes that make it possible to bind keys to mitigate this issue:

• ["core.esupports.metagen"].config.undojoin_updates = true - When true, we call :undojoin just before updating the updated: field in the metadata. With this set to true you can make a change, write the file and press u to undo your change and the timestamp update. But, you will still get another time stamp update after the undo. Making multiple undos in a row impossible b/c of branches. Enter: the second addition..
• require("neorg.modules.core.esupports.metagen.module").public.skip_next_update() - a function which will disable exactly one metadata 'updated at' update. This function can prevent the issue above, and makes it possible to remap the u and <c-r> keys so that they behave mostly normally in a norg doc with autosave.

This solution is maybe not the most elegant. I'm open to feedback on how to make it better, I threw this together quickly and without much thought after I realized that it would mostly work.

I'd like to test drive this for a few more days as well before it potentially gets merged.

Example Usage

--- config..
["core.esupports.metagen"] = {
  config = {
    undojoin_updates = true,
  },
},
--- config..
["core.keybinds"] = {
  config = {
    hook = function(keybinds)
      keybinds.map("norg", "n", "u", function()
        require("neorg.modules.core.esupports.metagen.module").public.skip_next_update()
        local k = vim.api.nvim_replace_termcodes("u<c-o>", true, false, true)
        vim.api.nvim_feedkeys(k, 'n', false)
      end)
      keybinds.map("norg", "n", "<c-r>", function()
        require("neorg.modules.core.esupports.metagen.module").public.skip_next_update()
        local k = vim.api.nvim_replace_termcodes("<c-r><c-o>", true, false, true)
        vim.api.nvim_feedkeys(k, 'n', false)
      end)
    end,
  },
},
--- config..

[benlubas]

I've used this for about a week and haven't had major issues with it.

This definitely feels like a hack. But I can't think of a better way to do this (other than, just don't use autosave in norg files).

[vhyrro]

Sounds like a good idea for the time being. I can't really think of any alternative solution either. Thank you!