wallet error handling

[jackielu3]

Description of Changes

Added a error throw to the HTTPWalletJSON.ts

Linked Issues / Tickets

Reference any related issues or tickets, e.g. "Closes #123".

Testing Procedure

Describe the tests you've added or any testing steps you've taken.

• I have added new unit tests
• All tests pass locally
• I have tested manually in my local environment

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have updated CHANGELOG.md with my changes
• I have run npm run doc and npm run lint one final time before requesting a review
• I have fixed all linter errors to ensure these changes are compliant with ts-standard
• I have run npm version patch so that my changes will trigger a new version to be released when they are merged