Type fragment inputs (for dict editor) despite errors

[wrzontek]

Describe your changes

This allows the fragment to be typed (e.g. for the purpose of DictParameterEditor / substitotor), if:

1. fragment is invalid due to having no output block
2. a process uses a fragment that does have an output but doesnt use that output (doesnt redirect the 'arrow')

Checklist before merge

• Related issue ID is placed at the beginning of PR title in [brackets] (can be GH issue or Nu Jira issue)
• Code is cleaned from temporary changes and commented out lines
• Parts of the code that are not easy to understand are documented in the code
• Changes are covered by automated tests
• Showcase in dev-application.conf added to demonstrate the feature
• Documentation added or updated
• Added entry in Changelog.md describing the change from the perspective of a public distribution user
• Added MigrationGuide.md entry in the appropriate subcategory if introducing a breaking change
• Verify that PR will be squashed during merge

[github-actions]

created: #5985
⚠️ Be careful! Snapshot changes are not necessarily the cause of the error. Check the logs.

[wrzontek]

(nondeterministic cypress error)

[wrzontek]

if possible, this could also go into release/1.15

[arkadius]

This error type looks hacky in this context. I'd rather expect sth like output of fragment is not used or sth similar. Is it easy to change? Can it be node error instead of global error?

[arkadius]

This error type looks hacky in this context. I'd rather expect sth like usage of/reference to invalid fragment . Is it easy to change? Can it be node error instead of global error?