Arlulacore

This Release updates some field names that were missed in the major release, but which are backwards compatible:
- On OrderRequest `res` is updated to `gsd`
- On DetailedOrderResult and OrderResult, `imagery_id` is updated to `ordering_id`

This release is adding pre-release support for the 2022-07 API update to ensure minimal disruption during change over.

This release:
- makes archive search's return type an object
- removes `eula` and `price` from search results
- renames search result `resolution` to `gsd` and `id` to `ordering_id`
- adds spectral `bands` information to search results (pending 2022-07 server release)
- adds ordering `bundles` allowing processing level selection (currently the existing default, addition options pending 2022-07 server release)
- adds `license` selection for different license types (currently the existing default, addition options pending 2022-07 server release)
- removes `seats` from order request
- adds `bundle_key` to order request
- changes pricing calculations for scenes (see documentation)

Detailed documentation for all these changes is available at
https://arlula.com/documentation/documentation-pre-release/

This release fixes some features of the API and adds comprehensive unit testing.
- Fixes request serialisation issues related to 5.
- Adds a lightweight RFC3339 parser to ensure timestamps are correctly parsed relating to 6.
- Adds unit tests for the archive and orders API as well as the RFC3339 parser.
- Fixes issues with setting webhooks and emails on OrderRequest objects.
- Ensures that files returned by OrderAPI.get_resource_as_file() are seeked to the beginning of the file and open for read and write.

This release changes the type hint on resolution for search requests to be required.

This release is a minor patch that fixes incorrect headers from the past version.
- It updates the user agent header to `2.0.1`
- It updates the x_api_version string to `2021-09`

This release updates the SDK to the API 2021-09 version and its subsequent bugfixes, it includes
- adding PEP 484 type hints for all API return objects (including the new fields for search results and resources)
- complex requests now take objects as arguments, which
- allowing chaining for construction of complex request parameters
- composes the archive and orders api's into a root "ArlulaAPI" session object
- adds the new search filters for "supplier", "cloud" and "offNadir"

This release introduces a number of breaking changes in an effort to approach a more standard structure, and corresponds to a major version update.