No text length validation in element popup

[ilchudov]

Description:
When a user edits the name of an element and enters more than 255 characters, the system does not display any validation error.

Steps to Reproduce:

1. Open VS Code extension or web UI;
2. Create chain and add any element to graph;
3. Edit the element name and enter a value longer than 255 characters (e.g., {{{}abcdefghijklmnopqrstuvwtsuywheoimdkakmloapywtvd,fmlekepw56253@#@-kwo20jejdbwxyz...{}}}).

E.R.: The system should display a validation error: “Value cannot exceed 255 characters.”

A.R.:
VS Code extension: No validation error is shown, and the system accepts the input exceeding 255 characters and then it hides the label name.
Web UI: Saving element is failed with backend exception.