Collation Mismatch Between Explicit Collations

``` SQL
CREATE TABLE tbl(a INT);
SELECT create_distributed_table('tbl', 'a');

SELECT * FROM tbl WHERE ('A' COLLATE "en_US.utf8") != 1::MONEY::VARCHAR(1);

ERROR: collation mismatch between explicit collations "en_US.utf8" and "default"
CONTEXT: while executing command on localhost:9701
```

Start by reproducing the SQL example against a distributed table and compare the behavior with the equivalent non-distributed query. Investigate how the explicit en_US.utf8 and default collations are handled when comparing the VARCHAR expression with the converted MONEY value; done means the intended comparison behavior is established without the reported collation mismatch.

Written by the indexing model from the issue text.