Feat(Core) : Add account upgrade method

[connorivy]

Description & motivation

Add method for account upgrade. This is to be used from manager

Changes:

To-do before merge:

Screenshots:

Validation of changes:

Checklist:

• [x] My pull request follows the guidelines in the Contributing guide?
• [x] My pull request does not duplicate any other open Pull Requests for the same update/change?
• [x] My commits are related to the pull request and do not amend unrelated code or documentation.
• [x] My code follows a similar style to existing code.
• [ ] I have added appropriate tests.
• [ ] I have updated or added relevant documentation.

References