Upper limit of 255 characters on the concept and form element names

Right now form element and concept names are varchar(255) and if the user tries to save the name of length more than 255 chars then the request fails on the DB.
Either we should increase this limit or the client should not allow users to type more than 255 characters

No files or tests are named. Start by tracing where concept and form element names are persisted and where the save request is handled, then check the PostgreSQL schema and any client-facing validation. Done means choosing and documenting one limit behavior and covering names longer than 255 characters without a database failure.

Written by the indexing model from the issue text.