fix: return storage mode submission version when when retrieving from server

[karrui]

Problem

Currently, the encrypted submission object returned does not return the version number, whilst formsg-javascript-sdk#decrypt requires the version number in the param (but not used since we only have 1 version so far).

This bug does not affect prod, since the version parameter is actually unused by the SDK. This is to prevent future updates from breaking and to correctly return expected required parameters when retrieving storage mode responses.

This PR returns the version number when retrieving submission (meta)data regardless so that the decrypt call doesn't need a mock version number parameter.

Closes #2029

Solution

Breaking Changes

• No - this PR is backwards compatible

Bug Fixes:

• add version key when retrieving storage mode submission data
• pass version on client when decrypting storage mode responses

Tests

Tests have been updated to account for the new version key returned.

Manual test

• View individual storage mode response. Should decrypt and display correctly
• Download storage mode response (without attachment). Should download correctly and correct responses decrypted.
• Download storage mode response. same as above.

[karrui]

@seaerchin this fixes the need to hardcode the version number in a Typescript file calling the SDK. However, this PR may also introduce conflicts. See which one gets merged first.