Add a new node that applies Style Preset templates to prompts in workflows.
The node takes a style preset ID and positive/negative prompts as inputs,
then replaces {prompt} placeholders in the template with the provided prompts.

This makes Style Preset templates accessible in Workflow mode, enabling
users to apply consistent styling across their workflow-based generations.

Adds a new StylePresetField type that enables dropdown selection of
style presets from the database in the workflow editor.

Changes:
- Add StylePresetField to backend (fields.py)
- Update Prompt Template node to use StylePresetField instead of string ID
- Add frontend field type definitions (zod schemas, type guards)
- Create StylePresetFieldInputComponent with Combobox
- Register field in InputFieldRenderer and nodesSlice
- Add translations for preset selection