Feature/improve sign tx latency

[HinsonSIDAN]

Summary

Improve wallet sign tx latency by storing account, not calculating everytime.

Scope of Change

• whisky-wallet

Type of Change

Feature Change

Type of feature change:

2. Breaking change - fix or feature that would cause existing functionality to not work as expected
   All wallet init function now returning result instead of pure wallet struct.

Maintenance

• Code refactoring (improving code quality without changing its behavior)

Additional Information

Need check compatibility issue with python and golang signing module, and update accordingly @twwu123