RPC tests for dapp staking

[niklabh]

Pull Request Summary

Added tests for:

1. Register contract on H160 address 0x1 using Alice account.
2. Bond & stake minimum staking amount on registered contract using Bob account.
3. Bond & stake an additional 500 tokens on the same contract using Bob account.
4. Unbond 250 tokens.
5. Ensure that at least a few blocks occur after step 3 (2 blocks should be enough).
6. Force a new era using a sudo call.
7. Claim dapp rewards for registered contract
8. Claim staker rewards for registered contract
9. Unbond 250 tokens.
10. Advance for UnbondingPeriod amount of eras until the first unbonding chunk can be withdrawn
11. Withdraw unbonded funds
12. Advance ONE era using sudo call
13. Withdraw the remaining unbonded chunk

Check list

• [x] added or updated unit tests
• [ ] updated Astar official documentation
• [ ] added OnRuntimeUpgrade hook for precompile revert code registration
• [ ] updated spec version
• [ ] updated semver

[hoonsubin]

@niklabh what is the status of this PR?

[niklabh]

Not able to merge this as commits were not signed with a gpg key. Merging is blocked for this PR. Creating a new one.