cql3: expr: expr::to_restriction: Handle token relations
cql3: expr: expr::to_restriction: Handle token relations

Implement converting token relations to expressions.

The code is mostly tekken from functions in token_relation.hh,
because we are replicating functionliaty of the functions called
token_relation::new_XX_restrictions.

Signed-off-by: cvybhu <b66a6f3989e26cb552db14b7ab163c3a50292e24@scylladb.com>

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