Burned rewards calculation

[bobo-k2]

Pull Request Summary

Fixed existing 'tokens to be burned' calculation to use real dApp tiers allocation.

The code goes from the first era in the current period 'till current_era - 1 and calculates how much reward are allocated for empty tiers slots (those are burned rewards). Those calculation is based on real data.

Second part of the calculations calculates the same from current_era until last era of the current period under assumption that we will have the same dApp tier allocations as in previous era. Since we are looking for total tokens to be burned this is the best we can. The more we are progressing till the end of the current period the more precise calculation will be.

Check list

• [ ] contains breaking changes
• [ ] adds new feature
• [x] modifies existing feature (bug fix or improvements)
• [ ] relies on other tasks
• [ ] documentation changes
• [ ] tested on mobile devices

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit f40ec50):

https://astar-apps--pr1269-fix-burned-rewards-w3lcu4xd.web.app

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[Kahonnohak]

Thanks @bobo-k2 I'll check & verify by manually adding tokens tomorrow!