storage-cassandra: the migration runner reports an UPDATE it doesn't handle as a statement that names no table #676

#638 has the Cassandra migration runner write the keyspace into each statement's table name, and fail a file when it can't (qualify_statement in crates/storage-cassandra/src/migrations.rs). The error is:

Migration file {filename} has a statement that names no table the runner can qualify with a keyspace: {first line}

That's wrong for a statement that names a table in a form the runner doesn't handle, such as UPDATE settings SET value = '1' WHERE key = 'a' or DROP TABLE settings. @jcshepherd pointed this out in review on #638 and suggested uses a statement form the runner does not support: <first line>. Supported: CREATE TABLE, CREATE INDEX, ALTER TABLE, INSERT INTO.

That wording would be wrong for statements that reach the same error in a form the runner handles:

• CREATE TABLE other.a (k int PRIMARY KEY), which already names a keyspace
• CREATE TABLE "Foo" (k int PRIMARY KEY), which quotes the table name
• /* header */ CREATE TABLE a (k int PRIMARY KEY), which opens with a /* */ comment the runner doesn't skip (storage-cassandra: the migration runner splits a file at a ; inside a comment or a string literal #675)

A message that names both causes is right for both groups:

Migration file {filename} has a statement the runner cannot qualify with a keyspace: {first line}. The runner supports CREATE TABLE, CREATE INDEX, ALTER TABLE and INSERT INTO, each naming an unquoted table without a keyspace.

rejects_statements_it_cannot_qualify only checks that each input fails. It should also check the message for one input from each group.