Implement missing prototypes

Some assets currently don't have prototypes and therefor cannot be created from scratch.

This issue tracks the implementation for them.

Currently needed:

• Database
• Experiment

Note that experiment can't be created from scratch so this use case is unsupported and should properly triggers an exception.

An experiment is based on a toolchain. Therefor providing a "prototype" doesn't make sense as its content would depend on what is available in the prefix. Also the person getting that "prototype" would first have to clear everything before it can start configuring the experiment as they would like.