Metadata identifier templates with slashes "/"

In **GeoNetwork**, it seems that it's not possible to have metadata identifiers with slashes.
Some portals expect to have unique identifiers like `https://www.myportal.com::{{uuid}}`.
Setting up such a template from the [Metadata identifier template](https://docs.geonetwork-opensource.org/4.2/administrator-guide/managing-metadata-standards/metadata-identifier/) administration works.
But then, when creating a metadata with such a template, the editor service throws an error of type
```
org.springframework.security.web.firewall.RequestRejectedException:
The request was rejected because the URL was not normalized.
```

I am wondering what core developpers think about this issue.

1. Do you think it's ok to have such metadata identifer templates ?
2. Do you think GeoNetwork should support that ?
3. Do you think that it's a bug right now ?
4. Why has the URL to be normalized ?
5. Would you imagine other potential drawbacks of fixing this issue ?

Thanks a lot for your expertise :pray:

Start by reproducing the metadata creation flow with an identifier template containing slashes, then trace the editor service request to the Spring Security firewall rejection. No source files or tests are identified in the issue; done would require a decided scope for supporting these templates, documented behavior, and regression coverage for the accepted or rejected identifier format.

Written by the indexing model from the issue text.