User-defined types can depend on each other, creating directed acyclic graph.
In order to support restoring schema from `DESC SCHEMA`, UDTs should be
ordered topologically, not alphabetically as it was till now.
This patch changes the way UDTs are ordered in `DESC SCHEMA`/`DESC KEYSPACE <ks>` statements, so the output can be safely copy-pasted to restore the schema.
Fixes#18539Closesscylladb/scylladb#18302
* github.com:scylladb/scylladb:
test/cql-pytest/test_describe: add test for UDTs ordering
cql3/statements/describe_statement: UDTs topological sorting
cql3/statements/describe_statement: allow to skip alphabetical sorting
types: add a method to get all referenced user types
db/cql_type_parser: use generic topological sorting
db/cql_type_parses: futurize raw_builder::build()
test/boost: add test for topological sorting
utils: introduce generic topological sorting algorithm
61505d057e