Pathway

Added
- `Schema` method `typehints` that returns dict of mypy-compatible typehints.
- Support for JSON parsing from CSV sources.
- `restrict` method in `Table` to restrict table universe to the universe of the other table.
- Better support for postgresql types in the output connector.

Changed
- **BREAKING**: renamed `Table` method `dtypes` to `typehints`. It now returns a `dict` of mypy-compatible typehints.
- **BREAKING**: `Schema.__getitem__` returns a data class `ColumnSchema` containing all related information on particular column.
- **BREAKING**: `tuple` reducer used after intervals_over window now sorts values by time.
- **BREAKING**: expressions used in `select`, `filter`, `flatten`, `with_columns`, `with_id`, `with_id_from` have to have the same universe as the table. Earlier it was possible to use an expression from a superset of a table universe. To use expressions from wider universes, one can use `restrict` on the expression source table.
- **BREAKING**: `pw.universes.promise_are_equal(t1, t2)` no longer allows to use references from `t1` and `t2` in a single expression. To change the universe of a table, use `with_universe_of`.
- **BREAKING**: `ix` and `ix_ref` are temporarily broken inside joins (both temporal and ordinary).
- `select`, `filter`, `concat` keep columns as a single stream. The work for other operators is ongoing.

Fixed
- Optional types other than string correctly output to PostgreSQL.

Added
- Support for messages compressed with zstd in the Kafka connector.

Added
- Support for JSON data format, including `pw.Json` type.
- Methods `as_int()`, `as_float()`, `as_str()`, `as_bool()` to convert values from `Json`.
- New argument `skip_nones` for `tuple` and `sorted_tuple` reducers.
- New argument `is_outer` for `intervals_over` window.
- `pw.schema_from_dict` and `pw.schema_from_csv` for generating schema based, respectively, on provided definition as a dictionary and CSV file with sample data.
- `generate_class` method in `Schema` class for generating schema class code.

Changed
- Method `get()` and `[]` to support accessing elements in Jsons.
- Function `pw.assert_table_has_schema` for writing asserts checking, whether given table has the same schema as the one that is given as an argument.
- **BREAKING**: `ix` and `ix_ref` operations are now standalone transformations of `pw.Table` into `pw.Table`. Most of the usages remain the same, but sometimes user needs to provide a context (when e.g. using them inside `join` or `groupby` operations). `ix` and `ix_ref` are temporarily broken inside temporal joins.

Fixed
- Fixed a bug where new-style optional types (e.g. `int | None`) were translated to `Any` dtype.

Fixed
- Incompatible `beartype` version is now excluded from dependencies.

Added
- Module `pathway.dt` to construct and manipulate DTypes.
- New argument `keep_queries` in `pw.io.http.rest_connector`.

Changed
- Internal representation of DTypes. Inputting types is compatible backwards.
- Temporal functions now accept arguments of mixed types (ints and floats). For example, `pw.temporal.interval` can use ints while columns it interacts with are floats.
- Single-element arrays are now treated as arrays, not as scalars.

Fixed
- `to_string()` method on datetimes always prints 9 fractional digits.
- `%f` format code in `strptime()` parses fractional part of a second correctly regardless of the number of digits.

Added

- `Table.cast_to_types()` function that can perform `pathway.cast` on multiple columns.
- `intervals_over` window, which allows to get temporally close data to given times.
- `demo.replay_csv_with_time` function that can replay a CSV file following the timestamps of a given column.

Fixed

- Static data is now copied to ensure immutability.
- Improved error tracing mechanism to work with any type of error.