Add blockfrost mode to hydra-chain-observer #5828

Job	Run time
Build & test (plutus-cbor)	1m 52s
Benchmarks (hydra-node, tx-cost, --output-directory $(pwd)/../benchmarks)	2m 56s
Build specification using nix	2m 12s
Benchmarks (hydra-node, micro, -o $(pwd)/../benchmarks/ledger-bench.html)	2m 16s
Build & test (plutus-merkle-tree)	1m 47s
Benchmarks (hydra-cluster, bench-e2e, datasets datasets/1-node.json datasets/3-nodes.json --outpu...	6m 0s
Build & test (hydra-plutus)	2m 17s
Build haddock using nix	1m 44s
Benchmarks (plutus-merkle-tree, on-chain-cost, $(pwd)/../benchmarks)	1m 58s
nix flake check	16m 33s
Build & test (hydra-tui)	3m 57s
Build & test (hydra-node)	10m 0s
Build & test (hydra-tx)	2m 27s
Build & test (hydra-cluster)	9m 9s
Publish benchmark results	5s
Publish test results	13s
Documentation	3m 17s
	1h 8m 43s

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