Fix type annotations the linter found to be wrong

Async ids come from `get_function_name`, which returns a string, but
were documented as numbers.

`setmetatable` in clusterio's compat module loses `LibCompat` on the
module return, so the require is cast.

`GuiData.__index` accepts a `DataKey` but emmylua needs that as an
index signature on the class.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_gui/module/data.lua

@@ -61,7 +61,8 @@ local GuiData = {
 --- @field element_data table<uint, table<uint, any>>
 --- @field player_data table<uint, any>
 --- @field force_data table<uint, any>
---- @field global_data table
+--- @field global_data table
+--- @field [DataKey] any
 -- This class has no prototype methods
 -- Same as raw but __index ensures the values exist