* bump cryptography to >40.0.1 in install_requires

* fix syntax

'__name__' -> __name__

'__name__' -> __name__

Fixes a subscription error if there is a space at the end of the identifier value

* Allow List,Union,Optional named fields

Fixes #1441

* use typing

* Make possible to not strip credentials in Client.server_url

* Make server_url a property

* Lint

* Update docstrings

* Remove init parameter

* Add type hints to the Node methods

* remove a duplicated import

* make `server` accept as Client

With the hook you can register callback method with the following type `CertificateValidatorMethod`:
```
Callable[[x509.Certificate, ApplicationDescription], Awaitable[None]]
```

The method should raise an `ServiceError` exception when the certificate is invalid.
The makes it possible to provide your own logic for validation.

An default implementation of such certificate validation hook is also provided by `ucrypto.validator.CertificateValidator`.

`CertificateValidator` supports checking:
- Uri
- Timerange
- Key Usage
- Extended Key Usage
- Trust
- Revoked

For the last two checks a instance of a `TrustStore` needs to be provided to `CertificateValidator`.

Which checks must be performed can be configured with `CertificateValidatorOptions`. Those are provide to the constructor of `CertificateValidator` and can be changed later with `CertificateValidator.set_validate_options`.

Examples of client and server with encryption are changed to demonstrate the use of the validator.

Basic testing of the validator is present.