Python-amazon-paapi

**Fixes:**
- Added browse_node_id to search mandatory args check.

**New features:**
- Added ``include_unavailable`` parameter to ``get_items`` to return unavailable items as part of the result.

**Improvements:**
- Items are correctly ordered based on the ``items`` parameter in ``get_items``, including duplicates.
- Avoid making extra API requests for duplicated items in ``get_items``.
- Lowercase ASIN code is now detected and automatically converted to uppercase.

**Minor changes:**
- AsinNotFoundException includes the search string
- Updated docstrings in exceptions

**New exceptions:**
- TooManyRequestsException: raised when requests limit is reached.
- InvalidPartnerTagException: raised if the partner tag is not present or invalid.
- AssociateValidationException: raised when credentials are not valid for the selected country.

**Updates:**
- InvalidArgumentException now is raised if returned from the API.

**Bug Fixes:**
- Solved bug with pagination args validation.

This version breaks compatibility with previous ones, so you will need to migrate in order to take advantage of the new features. You can continue using previous version, but a warning will appear to let you know that you should upgrade.

**New features:**
- Added type hinting to help you code.
- Added compatibility with all arguments from the official API.
- Now the full information from the API is returned, instead of a trimmed version.
- Added custom exceptions to help with error handling.
- Added models for some attributes.

**Breaking changes:**
- Adjusted all methods and models to meet Amazon API standards.
- Changed module name from amazon to amazon_paapi to avoid module clashes.
- Compatibility with Python 3.6 or later.

- Added compatibility for new link type.