test: add unit test for header submission #5951

Job	Run time
branch_name	2s
lint / markdown-lint	1m 9s
lint / golangci-lint	1m 9s
test / Build All Rollkit Binaries	2m 0s
test / Go Mod Tidy Check	23s
lint / yamllint	6s
test / Run EVM Execution Tests	2m 38s
lint / goreleaser-check	10s
lint / hadolint / hadolint	9s
proto / buf-check	7s
test / Run E2E System Tests	1m 14s
test / Run Unit Tests	3m 23s
release	0s
	12m 30s

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