Add RPC endpoint pool with failover support (#1209) #1471

Job	Run time
set-image	2s
Check documentation	4m 20s
Build polkadot-staking-miner binary	3m 56s
Check formatting	55s
Clippy	3m 12s
Check code	4m 55s
Run tests	3m 56s
Build and publish Docker image	41s
Test Docker image build	0s
	21m 57s

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