Reserve target allocation should be pulled from on-chain

[martinvol]

Contract calls involved are:

1. https://github.com/celo-org/celo-monorepo/blob/36be5623c8fe71d58d976d9a0a9032f6d8f9e423/packages/sdk/contractkit/src/wrappers/Reserve.ts#L61
2. https://github.com/celo-org/celo-monorepo/blob/36be5623c8fe71d58d976d9a0a9032f6d8f9e423/packages/sdk/contractkit/src/wrappers/Reserve.ts#L71

This would prevent us from having to update the allocation on every governance proposal involving changes in the portfolio.

[aaronmgdr]

celo-org/celo-monorepo#8461

[aaronmgdr]

This is Blocked by the release of next version of Contract kit. (1.3)