Opera-api

The new release of [opera-api](https://pypi.org/project/opera-api/0.5.6/) brings an additonal `OPERA_API_WORKDIR` env var for setting the working directory of the target user's TOSCA CSAR. This means that the user will not have to move to a specific dir anymore and will also be useful when starting xOpera API Docker container.

We are releasing a new version of [opera-api](https://pypi.org/project/opera-api/0.5.4/) which brings these new additions:

* The version of `opera` package dependency has been upgraded to `0.6.9`
* Public [ghcr.io/xlab-si/xopera-api](https://github.com/xlab-si/xopera-api/pkgs/container/xopera-api) Docker image
* Updated OpenAPI spec and OpenAPI generator
* Updated requirements
* Updated integration tests
* New environment variables
* Updated README info

The new release of [opera-api](https://pypi.org/project/opera-api/0.5.3/) has these new additions:

* The version of `xopera-opera` was upgraded to `0.6.8`
* Update OpenAPI spec for opera 0.6.8 and OpenAPI generator
* Update requirements
* Update integration tests
* Enable SwaggerUI only in debug mode
* Update README
* Implement CI/CD pipeline with semi-automated PyPI releases

*The version of `xopera-opera` remains unchanged at `0.6.6`*

This release has these new additions:

* API support for `opera diff` and `opera update`.
* API support for `opera validate <csar>`, a split endpoint from service template validation.
* The result returned by `/info` now contains all available CSAR and service template metadata.

It improves:

* The test suite now has a completely valid CSAR with complete metadata and a JSON-decoding trigger target.
* The test suite has been improved to be stricter and more sensitive to failures.

The following endpoints were deprecated pending removal in a future release:

* `/validate`, which performed service template diffs, is now deprecated in favour of the following two endpoints
* `/validate/servicetemplate` for service template validation,
* `/validate/csar` for CSAR validation.

This release has the following bugfixes:

* The service template filename was incorrectly passed to the underlying library function, causing a far-downstream type mismatch. The parameter is now passed through as the proper type.

*The version of `xopera-opera` has been updated to `0.6.6`*

This release has these new additions:

* API support for `opera deploy --clean-state`.