* 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When the data range of the certificate is no longer valid it generates a new certificate.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.

Those issues were not detected previously since they are linked to the
recent update of ruff to version 0.0.283, which fixed an issue in the
detection of this lint error.

* When reading Enumeration and OptionSet type definitions, also accept StructureDefinition instance.

This kind of type definition is "unclean" but not strictly forbidden by the standard.
Requires guessing of actual enum values:
- Count starting at 1 for Enums
- 0x1, 0x2, 0x4, ... for OptionSet

* add test for OptionSet defined via StructureDefinition

* load_enums: On unexpected errors, skip entry with error message

* fix test if not run in isolation