Bonus Reward

[mrbreo]

• implemented bonus reward feature for miners newly registered within 7 days eligible timeout
• added func_helper with linear function
• fetched miner uid and block_number
• updated base validator neuron
• added get_new_miner function
• added bonus_rewarder function
• fixed pkl bug on get_miner_uids function

[note]
new miners within the eligible timeout period (7 days) receive bonus incentives, which are calculated using a linear function based on miner age and gradually decrease to 0 by the end of the eligibility period.