Improve user experience

This merge request mainly includes changes that aim to improve the user experience.

Processes table:

• Allow deletion of individual processes
• Allow selection of multiple processes for subsequent deletion
• Automatically update status of processes
• Replace action links with drop-down menu

Process creation form:

• Show validation errors next to relevant input
• Preserve form inputs on validation errors
• Generate Docker-style tag if no tag is provided
• Validate tag as user types
• Show type-specific inputs based on type selection