Fix blocking IO issues in luxor_openapi_asyncio module

[DigitalBites]

Needed to update the template used to generate the rest.py file.

Enabled a check to see if configuration.ssl_context is provided and then use this context avoiding IO during default certificate configuration reads from the file system.

A new luxor_openapi_asyncio version 0.1.0 -> 0.2.0 or similar will need to be rolled so I can merge the one line change in the hass_luxor integration.

closes #3

[DigitalBites]

@dcramer thoughts on the above?

This was done with compatible changes for openapi generator openapi-generator-cli-5.2.1.jar (it seemed like this was what was used based on the files in the repo). I did try the latest and was getting some strange errors on number of parameters and reverted to the initial version you used which appears to continue to generate and work ok.