Optimization with user interest & conversion caching

[softmarshmallow]

Selection conversion to Reflect UI Node is required by user interest, and is not required when, for example, Icons loader is selected.

Also with node caching we can save converting resource, still few problem remains.

• Timestamp management for converted data cache
• Tree inspection logic to check if the node is actually changed and requires re-conversion
• Only convert the updated node (if possible)
• Q: Can we make tree inspection to check anything is updated as a cheap operation? (or will it be cheaper to just convert the whole tree? )
• Size management to ask user to update it again (e.g. "Your have selected a huge layer. Do you want to proceed?" + "You have selected a huge layer. Do you want to use cached version of it to save time?")

Related - https://github.com/gridaco/assistant/tree/optimize/with-user-interest