cql3: create_view_statement: validate bound variables at prepare step
cql3: create_view_statement: validate bound variables at prepare step

Variables specification is already known at prepare step, so
it's safe to move the check to happen as early as possible.

Tests: unit(dev)

Signed-off-by: Pavel Solodovnikov <2cf5887fafb117b7ff3e29b9720a7305c3313494@scylladb.com>
Message-Id: <20210802090852.253469-1-2cf5887fafb117b7ff3e29b9720a7305c3313494@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla