Add MonadIO instance for EIO

I am not sure if this is possible. The first hurdle is getting an applicative and monad instance. The naive applicative implementation gives this error:
```idris
src/EIO.hs:54:15-54: error:
• Couldn't match type ‘e’ with ‘e <> e’
Expected: EIO e b
Actual: EIO (e <> e) b
‘e’ is a rigid type variable bound by
the instance declaration
at src/EIO.hs:53:10-28
• In the expression: af >>= \ f -> ax >>= \ x -> return (f x)
In an equation for ‘<*>’:
af <*> ax = af >>= \ f -> ax >>= \ x -> return (f x)
In the instance declaration for ‘Applicative (EIO e)’
• Relevant bindings include
ax :: EIO e a (bound at src/EIO.hs:54:10)
af :: EIO e (a -> b) (bound at src/EIO.hs:54:3)
(<*>) :: EIO e (a -> b) -> EIO e a -> EIO e b
(bound at src/EIO.hs:54:6)
|
54 | af <*> ax = af >>= \ f -> ax >>= \ x -> return (f x)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```

Start by reading src/EIO.hs around lines 53-54 and the existing EIO definition to understand how its error type is combined. Investigate whether Applicative, Monad, and MonadIO instances can satisfy the type constraints shown in the compiler error. Done means the requested instances compile without the reported mismatch.

Written by the indexing model from the issue text.