Feat: default on_click for some components

[teto]

Requested feature

I think it would make sense for some component to have a default on_click implementation.

Right now, I have added some code for the following components:

• branch: copy the branch name on click
• filename copy the buffer filename on click

      lualine_b = {
          {
              'filename',
              path = 1,
              -- takes a function that is called when component is clicked with mouse.
              on_click = function(_nb_of_clicks, _button, _modifiers)
               local filename = vim.fn.getreg('%')
                  print('copying filename to clipboard: '..filename)
                  vim.cmd("call provider#clipboard#Call('set', [ ['".. filename .."'], 'v','\"'])")
              end,
          },
      },

• i also have a custom https://github.com/tpope/vim-obsession component that toggles saving the session when clicking an icon.

Feel free to close if you think it's out of scope.

[shadmansaleh]

I don't think it's a bad idea to add some default on clicks. But uses of on-click seem quite user-specific. Current way of using on-click isn't exactly hard so, for now, I'll leave it up to the users to decide what they want to do with it. If some well-accepted pattern appears as use case for this I'm open to adding that as default behavior in future.

[teto]

I dont advocate to add one for every component (though having an extra feature rather than none should not be an issue from a UX perspective) but I think the "copy filename" case is quite a compelling one ? I could send PR if you agree.