feat: rearrange submissions storage map and apply more submission limits#14

tlovell-sxt wants to merge 4 commits into

feat/pallet-migrationsspaceandtimefdn/sxt-node:feat/pallet-migrationsfrom

feat/one-submission-per-account-per-batchspaceandtimefdn/sxt-node:feat/one-submission-per-account-per-batchCopy head branch name to clipboard