Exact classes can have fields injected when used as parameters to funcitons

Nobody has claimed this yet.

Love the new exact class! When using it though, I noticed that I could still 'inject' fields into an exact class when it is used as the input to a function. Example:

```
---@class (exact) TestClass
---@field public a number
---@field public b string
---@field public c boolean

---@param test_param TestClass
local function test(test_param)
end

test({a = 1, b = "2", c = true, d = 4})
```
causes no error.

I am not sure if this is intended or not, but I would expect to get an warning like: ```Fields cannot be injected into the reference of `TestClass` for `d`. To do so, use `---@class` for `test_param`.Lua Diagnostics.(inject-field)``` here.

Reproduce the provided Lua snippet in lua-language-server and inspect the exact-class handling for function parameter type checking. Done when passing an extra d field to TestClass produces the requested inject-field diagnostic, while the declared a, b, and c fields remain accepted.

Written by the indexing model from the issue text.