Move YNAB4/5 import code into loot-core (#1208)

packages/import-ynab4/README.md

packages/import-ynab4/index.js

packages/import-ynab4/package.json

packages/import-ynab5/README.md

packages/import-ynab5/example.json

packages/import-ynab5/index.js

packages/import-ynab5/package.json

packages/loot-core/package.json

packages/loot-core/src/platform/server/sqlite/index.d.ts

...es/loot-core/src/platform/server/sqlite/index.electron.ts

packages/loot-core/src/platform/server/sqlite/index.web.ts

packages/loot-core/src/server/cloud-storage.ts

packages/loot-core/src/server/db/index.ts

packages/loot-core/src/server/importers/actual.ts

packages/loot-core/src/server/importers/index.ts

packages/loot-core/src/server/importers/ynab4-types.d.ts

packages/loot-core/src/server/importers/ynab4.ts

packages/loot-core/src/server/importers/ynab5-types.d.ts

packages/loot-core/src/server/importers/ynab5.ts

packages/loot-core/src/server/main.ts