Loading schemas of views and indexes was not supported, with either `--schema-file`, or when loading schema from schema sstables.
This PR addresses both:
* When loading schema from CQL (file), `CREATE MATERIALIZED VIEW` and `CREATE INDEX` statements are now also processed correctly.
* When loading schema from schema tables, `system_schema.views` is also processed, when the table has no corresponding entry in `system_schema.tables`.
Tests are also added.
Fixes: #16492Closesscylladb/scylladb#16517
* github.com:scylladb/scylladb:
test/cql-pytest: test_tools.py: add schema-loading tests for MV/SI
test/cql-pytest: test_tools.py: extract some fixture logic to functions
test/cql-pytest: test_tools.py: extract common schema-loading facilities into base-class
tools/schema_loader: load_schema_from_schema_tables(): add support for MV/SI schemas
tools/schema_loader: load_one_schema_from_file(): add support for view/index schemas
test/boost/schema_loader_test: add test for mvs and indexes
tools/schema_loader: load_schemas(): implement parsing views/indexes from CQL
replica/database: extract existing_index_names and get_available_index_name
tools/schema_loader: make real_db.tables the only source of truth on existing tables
tools/schema_loader: table(): store const keyspace&
tools/schema_loader: make database,keyspace,table non-movable
cql3/statements/create_index_statement: build_index_schema(): include index metadata in returned value
cql3/statements/create_index_statement: make build_index_schema() public
cql3/statements/create_index_statement: relax some method's dependence on qp
cql3/statements/create_view_statement: make prepare_view() public
69a68e35dd