Read the schema's constraints in the property panel #8510

Task Summary

The schema annotations this work declares, so that a configuration can be derived from an operator's own metadata, describe more than the verification needs: which columns a property may name, which values a hyperparameter accepts, which properties may not repeat across rows. The property panel does not read them, so a user still gets a free text box where the schema knows the answer, and learns a value was wrong only when the workflow fails to compile.

A column property is checked against the attribute type rule for every column it names rather than only the first. A hyperparameter's value renders as the control its parameter implies: a dropdown where the accepted set is known, a number input where it is numeric, a plain text box where the rules say nothing. A property declared unique among rows says which row already holds the value, and a row deleted clears the error it left behind, since deleting a row changes no surviving control's value.

Step 26 of 27 in #8325. It touches no Scala and stands on its own.