* 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.

* add browse_nodes to SyncClient

* fix ruff E721 warning

In validates against trusted certificate, trusted ca certificates and certificate revocation lists.

I think types_aiofiles was a typo. I can only install types-aiofiles module.

"The 'warn' method is deprecated, use 'warning' instead"

With PR #1368 some functions are added to create and request certificates.
Based on those functions a new helper method `setup_self_signed_certificate` is created.
This should make it easy to add basic support to clients and servers for generating automatically certificates.

If can generated a private key and self-signed certificate when not already present.
When the data range of the certificate is no longer valid it generates a new certificate.

Both the examples for client and server use with encryption are updated to demonstrate the use.

"Coroutine 'set_security_string' is not awaited" it is an async function.