Support disabling specific endpoints

Pyctuator now supports disabling specific endpoints such as "environments".
This is done by specifying the endpoints to be disabled as follows:

pyctuator = Pyctuator(
    app,
    "Example FastAPI",
    app_url=f"http://{example_app_address}:8000",
    pyctuator_endpoint_url=f"http://{example_app_address}:8000/pyctuator",
    registration_url=f"http://{example_sba_address}:8080/instances",
    app_description=app.description,
    disabled_endpoints=Endpoints.ENV | Endpoints.HTTP_TRACE
)

Upgrade dependencies and support composite health-provider

• Upgrade many of the dependencies to much newer version
• Fix github workflow to use newer ubuntu runner
• Support multiple DB connections by naming respective health-provider and composing them

Upgrade python and libraries

Upgrade dependencies recommended by pyctuator show -o.

Upgrade python and libraries and more

In this major release we've finally upgraded Python to 3.9 and libraries to a recent versions, see #81.

In addition:

• This release improves the HTTP status code returned from the "health" endpoint, see #79.
• For maintainers - Major improvement to E2E's stability by using distinct TCP port for each test.

Enable customizing the scrubbing of secrets from environment variables and other properties

See https://github.com/SolarEdgeTech/pyctuator/tree/master/examples/Advanced#secret-scrubbing for details.

Support requiring authentication by customization of the integration with web-framework

See #67

Enable using custom SSL context for registration with SBA

See #65

Fix DB healthcheck to support Oracle

Pyctuator now uses Alchemy's ping method to test DB health as suggested in #61 - this solves an issue with monitoring connections to Oracle.

Additional app details

Pyctuator now allows adding arbitrary details to the "Info" section in SBA.
See documentation at https://github.com/SolarEdgeTech/pyctuator#additional-application-info

Bugfix - first SBA registration should be async

First SBA registration was done on the "main thread" so any communication issue blocked the application from starting.
Instead, the first registration attempt is now async as all the subsequent registrations were.