TypeError instance for Tuple

A coworker had a bug where they wrote:

```haskell
from $
Table @Foo
`InnerJoin`
Table @Bar
`on`
( \(foo, bar) -> foo ^. FooId ==. bar ^. BarFooId
)
```

The error was pretty gnarly.

```
Could not deduce (Database.Esqueleto.Experimental.ToInnerJoin
Database.Esqueleto.Experimental.NotLateral
(E.From (E.SqlExpr (Entity Foo)))
(E.From (E.SqlExpr (Entity Bar)))
(E.SqlExpr (Entity Foo), E.SqlExpr (Entity Bar)))
```

If we had a type error instance with `ToInnerJoin a b c (d, e)` then we may be able to provide a better error mesage.

Start by locating the ToInnerJoin type and its related instances, then reproduce the query and current type error shown in the issue. Define done as producing a more helpful diagnostic for tuple-shaped join expressions, and add or run a focused type-checking test if the repository provides one.

Written by the indexing model from the issue text.