feat(pack)!: suggest "delete" code action only for not active plugins

Problem: Deleting active plugins can lead to a situation when it is
  reinstalled after restart.

Solution: Suggest "delete" code action only for not active plugins.
  Whether a plugin is not active is visible by a hint in its header.

runtime/lua/vim/pack.lua

@@ -1161,8 +1161,9 @@ end
 ---           show more information at cursor. Like details of particular pending
 ---           change or newer tag.
 ---         - 'textDocument/codeAction' (`gra` via |lsp-defaults| or |vim.lsp.buf.code_action()|) -
----           show code actions available for "plugin at cursor". Like "delete", "update",
----           or "skip updating".
+---           show code actions available for "plugin at cursor".
+---           Like "delete" (if plugin is not active), "update" or "skip updating"
+---           (if there are pending updates).
 ---
 ---       Execute |:write| to confirm update, execute |:quit| to discard the update.
 ---     - If `true`, make updates right away.

runtime/lua/vim/pack/_lsp.lua

@@ -151,7 +151,9 @@ methods['textDocument/codeAction'] = function(params, callback)
       new_action('Skip updating', 'skip_update_plugin'),
     }, 0)
   end
-  vim.list_extend(res, { new_action('Delete', 'delete_plugin') })
+  if not vim.pack.get({ plug_data.name })[1].active then
+    vim.list_extend(res, { new_action('Delete', 'delete_plugin') })
+  end
   callback(nil, res)
 end
 
@@ -161,7 +163,7 @@ local commands = {
   end,
   skip_update_plugin = function(_) end,
   delete_plugin = function(plug_data)
-    vim.pack.del({ plug_data.name }, { force = true })
+    vim.pack.del({ plug_data.name })
   end,
 }