Adds unit tests for the function `expr::prepare_expression`.
Three minor bugs were found by these tests, both fixed in this PR.
1. When preparing a map, the type for tuple constructor was taken from an unprepared tuple, which has `nullptr` as its type.
2. Preparing an empty nonfrozen list or set resulted in `null`, but preparing a map didn't. Fixed this inconsistency.
3. Preparing a `bind_variable` with `nullptr` receiver was allowed. The `bind_variable` ended up with a `nullptr` type, which is incorrect. Changed it to throw an exception,
Closes#11941
* github.com:scylladb/scylladb:
test preparing expr::usertype_constructor
expr_test: test that prepare_expression checks style_type of collection_constructor
expr_test: test preparing expr::collection_constructor for map
prepare_expr: make preparing nonfrozen empty maps return null
prepare_expr: fix a bug in map_prepare_expression
expr_test: test preparing expr::collection_constructor for set
expr_test: test preparing expr::collection_constructor for list
expr_test: test preparing expr::tuple_constructor
expr_test: test preparing expr::untyped_constant
expr_test_utils: add make_bigint_raw/const
expr_test_utils: add make_tinyint_raw/const
expr_test: test preparing expr::bind_variable
cql3: prepare_expr: forbid preparing bind_variable without a receiver
expr_test: test preparing expr::null
expr_test: test preparing expr::cast
expr_test_utils: add make_receiver
expr_test_utils: add make_smallint_raw/const
expr_test: test preparing expr::token
expr_test: test preparing expr::subscript
expr_test: test preparing expr::column_value
expr_test: test preparing expr::unresolved_identifier
expr_test_utils: mock data_dictionary::database