Showing the strength of the blockchain

It happens quite often in telegram channel that people look for approaches how to solve their task, and quite often it happens that the existing features can already help to realize it. The reference UI should show the strength of the blockchain, and currently it mostly leverages the exchange. The showcases intend to open new possibilities.

Timed transfers

Setting the review period of a propopsal enforces that it (if approved) executes exactly at its expiration time. This can be used to create transfers that execute at a certain time.

Specification

User must be able to

- see a descriptive text that explains the leveraging of the proposal system and the fee breakdown (propose, approval and transfer fee) and warn that this is likely unsuitable for gateway deposits (different way to recognize the transfer required)
- enter target account, asset and amount and the desired execution time, optional a memo
- toggle "repeat daily/weekly for X times"

Tasks

- [ ] Create mockup for component and tile for #1857
- [ ] Implement design
- [ ] Implement business logic

This issue is also for discussion and feedback collection and part of #1857