fix(lsp): add spacevim.diagnostic function

close https://github.com/SpaceVim/SpaceVim/issues/4556

autoload/SpaceVim/lsp.vim

@@ -49,7 +49,7 @@ if (has('nvim-0.5.0') && s:NVIM_VERSION.is_release_version()) || has('nvim-0.6.0
     lua vim.lsp.buf.implementation()
   endfunction
   function! SpaceVim#lsp#show_line_diagnostics() abort
-    lua vim.lsp.diagnostic.show_line_diagnostics()
+    lua require('spacevim.diagnostic').open_float()
   endfunction
   function! SpaceVim#lsp#list_workspace_folder() abort
     let workspace = luaeval('vim.lsp.buf.list_workspace_folders()')

lua/spacevim/diagnostic.lua

@@ -0,0 +1,18 @@
+local M = {}
+
+-- The following have been replaced by |vim.diagnostic.open_float()|.
+--
+-- *vim.lsp.diagnostic.show_line_diagnostics()*
+-- *vim.lsp.diagnostic.show_position_diagnostics()*
+
+function M.open_float()
+    if vim.diagnostic ~= nil then
+        vim.diagnostic.open_float()
+    else
+        vim.lsp.diagnostic.show_line_diagnostics()
+    end
+
+end
+
+
+return M