Way to annotate `@overload` only table, instead of the entire `@class`

Nobody has claimed this yet.

```lua
---@class Class
---@overload fun(): self|Class
local Class = {}

local c = Class()

local unknown = c() -- but unknown is Class
```

I thought that was the indication `self/Class` was responsible for this

`self` for object
`Class` for table

But today I discovered that this is not so.
And in previous versions as well

In principle, this can be achieved by explicitly making

```lua
---@cast Class Class|fun(): Class
```

But for long names it is extremely monstrous

Reproduce the issue's Lua snippet in the language server and trace how @class and @overload annotations are interpreted. Determine how an overload can apply to the class table without changing the instance type, then add coverage for the example and verify that the inferred type of unknown is Class.

Written by the indexing model from the issue text.