Prettify nodes in editor

[Doralitze]

• [ ] We should only display the configuration symbol if there is actually any configuration to edit.
• [ ] Furthermore we should enforce a reasonable minimum size, such that one can actually drag them instead of clicking actions in case of a too small node.
• [x] It would be also beneficial to display the filter type within the node, for example below the id.
• [x] Last but not least we should visualize the required terminal data types.