Rtbhouse-sdk

- [breaking change] current `viewability` metric has been renamed to `ssp_viewability`. We are leaving compatibility layer in the api until 2024-12-31.
- added audio related metrics: `audio_complete_listens`, `ecpl`, `acr`.
- added viewability related metrics: `viewability_measurability`, `viewability_viewability`, `evcpm`.
- added visits related metrics: `visits_count`, `cpvisit`.

- [breaking change] Stats (`schema.Stats`, returned from `get_rtb_stats` and `get_summary_stats`) metrics: `imps_count`, `clicks_count`, `conversions_count`, `video_complete_views` are now represented as float type, to reflect actual api responses. Fractional metrics may appear in certain scenarios, eg. for custom grouping and/or as a result of manual adjustment.

- Added `utc_offset_hours` parameter for `get_rtb_stats` and `get_summary_stats`

- Added support for Pydantic v2
- [breaking change] `cookie_hash`, `last_click_time` and `last_impression_time` fields in `Conversion` schema are now nullable
- [breaking change] fixed naming convention compliance for fields in schemas: `rateCardId` (`UserInfo`) is now `rate_card_id` and `customProperties` (`Offer`) is now `custom_properties`

- Removed [inflection](https://pypi.org/project/inflection/) from the project dependencies
- Added `camelize` and `underscore` helper functions

- Dropped support for python 3.7 (which is reaching end-of-life), please use python 3.8.1+, v9 branch with python 3.7 compatibility will be updated until 2023-06-27
- Added support for python 3.11
- Unfrozen httpx, httpcore has been fixed