fix: split staking reserve acc by staking denom

[dongsam]

Description

closes: #220

Tasks

• Add AddressType, DeriveAddress
• Refactor StakingReservePoolAcc, to using DeriveAddress and StakingCoinDenom
• Add TotalStakingsRecords
• Update Invariant for TotalStakingsAmount
• Deprecate global StakingReserveAcc
• Set default ReserveAddressType
• Add testcases
• Refactor relevant functions
• Resolve in-line todo list
• Update docs and spec

References

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