Got Unimplemented input type when running queries with cal type variables in interactive shell

- EdgeDB CLI Version: 1.0.0-rc.2
- EdgeDB Version: edgedb/edgedb:1-rc2
- OS Version: arch linux

Steps to Reproduce:

1. edgedb -I ...
2. run the following queries
```edgedb> SELECT ($foo);
Unimplemented input type 00000000-0000-0000-0000-00000000010c
edgedb> SELECT ($foo);
Unimplemented input type 00000000-0000-0000-0000-00000000010b
edgedb> SELECT ($foo);
Unimplemented input type 00000000-0000-0000-0000-00000000010d
edgedb> SELECT ("2021-11-11");
{'2021-11-11'}
```

You cant test queries with variables of cal type, you can hard code the values though.