Make block_number field required for pre-confirmed events and receipts.#325

cchudant wants to merge 3 commits intostarkware-libs:release/v0.9.0-rc.3starkware-libs/starknet-specs:release/v0.9.0-rc.3from

cchudant:patch-2cchudant/starknet-specs:patch-2Copy head branch name to clipboard