test: Integration test for RemoveMultistakingBondDenom

[hieuvubk]

integration test for realiotech/multi-staking#153

Test scenario:

• create rio and rst validator
• create 2 validator more with an evm token
• users delegate to both 2 vals
• submit proposal to remove evm token as multistaking bonded token
• check undelegation for validator's self delegate and user delegate was created
• check evm token was returned to user after unbonding period
• check validator state after unbonding period

[facs95]

why this change?

[hieuvubk]

large and not integer weight value, just want to make sure rounding correctly.