Add minimum stake requirement

[Mosas2000]

Prevent spam stakes by adding minimum:

• MIN_STAKE constant (e.g., 1 STX)
• Validation in place-yes-stake and place-no-stake
• Error code for below minimum

[Yusufolosun]

Good day Maintainer
I would love to take on this issue, I've reviewed the issue description and I can implement a maintainable solution fast.
I'm active and i respond and react to feedback fast