Modularize service domain modules

[yvette-carlisle]

Summary

• split add_event service and validation into focused modules
• split ingestion profile admin and storage code into focused modules
• split sharing grant and publish paths into focused modules

Validation

• cargo make check after add_event/service split: 403 passed, 92 skipped
• cargo make check after add_event/validation split: 403 passed, 92 skipped
• cargo make check after ingestion_profiles/admin split: 403 passed, 92 skipped
• cargo make check after ingestion_profiles/storage split: 403 passed, 92 skipped
• cargo make check after sharing/grants split: 403 passed, 92 skipped
• cargo make check after sharing/publish split: 403 passed, 92 skipped
• final cargo make check after rebase: 403 passed, 92 skipped