Dropdown selectors for predefined field values in Workflows

Use dropdown selectors instead of free-text inputs for predefined field values in Workflows

When configuring branch conditions or filters in Workflows, fields with a fixed set of values (e.g., ticket state, priority) display a free-text input field. This forces users to type values from memory, which is error-prone and slow. There's no way to discover what valid options exist without leaving the workflow builder: