Add/Show/Delete Emojis on Notes (#181)

This MR adds the ability to view, add, and delete emojis from notes and comments.

This action can be performed by default with the `Ea` (emoji add) keybinding, and the `Ed` (emoji delete) keybinding. Only emojis added by the current user are eligible for deletion. The MR also implements a popup functionality which shows the user who added emojis on hover.

Implements #179

lua/gitlab/actions/discussions/signs.lua

@@ -267,7 +267,6 @@ M.parse_signs_from_discussions = function(discussions)
         start_line = start_old_line
         end_line = end_old_line
       else
-        vim.print(start_type == "")
         return {}, {}, string.format("Unsupported line range type found for discussion %s", discussion.id)
       end