Fixes #39584, allowing execution of arbitrary HQL queries in the current Hibernate ORM context.

The UI is very similar to the existing Agroal (SQL) database view (many thanks to @phillip-kruger for the inspiration 🙏) but allows selecting Hibernate persistence units and their entities, displaying existing data and executing custom HQL queries.

Data is rendered using native marshalling for now; this is ok for basic result types or simple entities, but it will not do for more complex models (e.g. circular associations, laziness, et.al.). I'm also working on a custom Hibernate tool that allows transforming query results to a textual (JSON) format and account for these complexities - I will update this interface to use that once it's available.