WorkspaceName is far too permissive

[bwaidelich]

We use a lot of value objects with Neos 9.0. One of the reasons for that is a better type safety.
For example: Because we know, that NodeAggregateId can't contain certain characters, we can safely use them for delimiters (e.g. in Cache entry/tag identifiers).

The constraints for WorkspaceName are really loose currently: /^[\p{L}\p{P}\d \.]{1,200}$/u (basically 1 - 200 characters of any class).

We should reduce length (how many characters are allowed) and width (which characters are allowed) drastically IMO.
As a side effect we could decide to omit the SHA1 hashing for cache tags

[mhsdesign]

Also related, during the discussion of exposing the workspace name in the node we considered the idea of virtual workspace names:

WorkspaceName::fromString() must be stricter without colons (so that we could allow in the future for extension, e.g. WorkspaceName::detached(ContentStreamid $csId) (with an internal representation like “cs:”)

idk if this is still legit as the discussion is age old now and we only wanted to limit it to be able to implement future ideas