Improve aggregator coverage

[carte7000]

No description provided.

[github-actions]

Code coverage report:

Package	main	simon/aggregator/unit-tests-4
aggregator	39.54%	61.95%
cciptestinterfaces	100.00%	100.00%
ccv-evm	0.00%	0.00%
cmd	0.00%	0.00%
executor	36.32%	58.84%
indexer	32.62%	35.83%
integration	4.27%	4.47%
protocol	42.95%	49.02%
verifier	43.47%	47.45%

[github-actions]

E2E Smoke Test Results

Test Case	Status	Duration
TestE2ESmoke/extra_args_v2/src->dst_msg_execution_eoa_receiver	pass	21.72s
TestE2ESmoke/extra_args_v2/dst->src_msg_execution_eoa_receiver	pass	19.72s
TestE2ESmoke/extra_args_v2/1337->3337_msg_execution_mock_receiver	pass	20.72s
TestE2ESmoke/extra_args_v2	pass	62.16s
TestE2ESmoke/extra_args_v3/EOA_receiver_and_default_committee_verifier	pass	19.72s
TestE2ESmoke/extra_args_v3/EOA_receiver_and_secondary_committee_verifier	pass	19.72s
TestE2ESmoke/extra_args_v3/receiver_w/_secondary_verifier_required	pass	20.22s
TestE2ESmoke/extra_args_v3/receiver_w/_secondary_required_and_tertiary_optional_threshold=1	pass	19.72s
TestE2ESmoke/extra_args_v3/receiver_w/_default_required,_secondary_and_tertiary_optional,_threshold=1,_message_specifies_all_three	pass	20.72s
TestE2ESmoke/extra_args_v3/receiver_w/_default_required,_secondary_and_tertiary_optional,_threshold=1,_message_specifies_default_and_secondary	pass	19.72s
TestE2ESmoke/extra_args_v3/receiver_w/_default_required,_secondary_and_tertiary_optional,_threshold=1,_message_specifies_default_and_tertiary	pass	19.72s
TestE2ESmoke/extra_args_v3/EOA_receiver_and_default_committee_verifier#01	pass	20.22s
TestE2ESmoke/extra_args_v3/max_data_size	pass	19.72s
TestE2ESmoke/extra_args_v3/EOA_receiver_and_default_committee_verifier_with_token_transfer	pass	19.73s
TestE2ESmoke/extra_args_v3	pass	199.21s
TestE2ESmoke	pass	261.64s

Full logs are available in the workflow artifacts.