Improve error message for invalid argument types

Nobody has claimed this yet.

Currently, when a function call has invalid arguments, the error is emitted in relation to the entire argument struct.

Example:

```
let printMessage (:message String) = print message

let main () = printMessage (:message 10)
// ^^^^^^^^^^^^^ invalid_argument_type
```

For single arguments functions this is not a big problem, but when one of the arguments match while the others don't, it may be confusing.

Example

```
let printUser (:name String, :age int) = print name

// The error is emitted to the entire struct, but only
// the age is invalid.
let main () = printMessage (:name "Joe", :age "10")
// ^^^^^^^^^^^^^^^^^^^^^^^^ invalid_argument_type
```

We should distinguish every problem with the passed argument and give more specific error messages.

No source file, test, or entry point is named in the issue. Locate the argument type-validation and diagnostic code, then inspect how mixed valid and invalid arguments are reported. Done means each invalid argument is identified separately with a more specific error message.

Written by the indexing model from the issue text.