EPIC: Multiplier points calculation

[0x-r4bbit]

This epic summarises issues and tasks related to the multiplier points calculation. We'll close this once all related issues are closed.

• [x] https://github.com/logos-co/staking/issues/48
• [ ] https://github.com/logos-co/staking/issues/98
• [x] https://github.com/logos-co/staking/issues/99