feat(seedless-onboarding): add dataType support for secret data items

[huggingbot]

Explanation

The metadata service now supports a dataType column for categorizing secret data (PrimarySrp, ImportedSrp, ImportedPrivateKey). This enables clients to distinguish between different types of backed-up secrets

Changes include:

• Add dataType parameter to insert operations
• Add updateSecretDataItem and batchUpdateSecretDataItems for updating existing items
• Update fetchAllSecretData to return storage metadata (itemId, dataType) alongside secret data
• Refactor SecretMetadata to separate local metadata from storage-level metadata

References

https://consensyssoftware.atlassian.net/browse/SL-350

Checklist

• [x] I've updated the test suite for new or updated code as appropriate
• [x] I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• [x] I've communicated my changes to consumers by updating changelogs for packages I've changed
• [x] I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them