Feat[C-Bridge]: Implement additional JSON-metric "status" values

[guidiaz]

• up-and-restarted: every time the bridge gets restarted
• wit-utxos-low: if number of utxos above threshold goes below 10
• wit-balance-low: if less than 3 days before running out of wits, according to average hourly expenditure
• evm-balance-leak: if the evm balance decreased during last polling period.