Enable bonding of LSM shares and atom LSTs

[zmanian]

Enables solvers to bond using not just native ATOM but also:

• LSM (Liquid Staking Module) shares from Cosmos Hub
• LST tokens (stATOM from Stride, qATOM from Quicksilver, stkATOM from pSTAKE)

Key changes:

• Add BondAsset types with support for native ATOM, LSM shares, and LSTs
• Implement configurable valuation with LSM discount (95%) and LST exchange rates
• Update RegisterSolver to accept multi-asset bonds
• Update DeregisterSolver to return all bond asset types
• Implement proportional multi-asset slashing
• Add AddBond and WithdrawBond execute messages for bond management
• Add UpdateLsmConfig and UpdateLstConfig for admin configuration
• Add SolverBond, LsmConfig, LstConfig, AcceptedLstTokens queries
• Update SPECIFICATION.md with LSM/LST bonding documentation

Benefits for solvers:

• Capital efficiency (earn staking yields while bonding)
• Flexibility (use existing staked positions)
• Lower opportunity cost (no need to unstake)