Log Message:
py-pygls: updated to 0.9.1

0.9.1

Added
- Functions to convert positions from and to utf-16 code units
- Type definitions for `ClientInfo` and `HoverParams`

Changed
- Exit server normally when `ctrl+c` is pressed in command shell.
- Mark deprecated `rangeLength` optional in `TextDocumentContentChangeEvent`
- Optimize json-rpc message serialization
- Fix `__init__()` constructors in several interface types
- Fix valueSet type in `SymbolKindAbstract`

Fixed
- `coroutine` deprecation warning - use async def instead