[ENHANCE] Add extension wallet handling for Cart transactions

[lachlanglen]

Summary

As a user using an extension wallet, e.g. Meteor extension, transactions don't involve a redirect and therefore the app fails to detect when I have signed a transaction. A polling mechanism like the one here can be used to poll on-chain for the expected state update and update the UI accordingly.

Motivation

[More detailed explanation of the motivation for the enhancement, including any benefits it would provide]

Description

[Detailed description of the enhancement, including how it would work and any design considerations]

Alternatives

[Discussion of any alternative solutions that were considered and why the proposed solution is preferred]

Risks

[Identification and mitigation of any potential risks associated with the enhancement]

Acceptance Criteria

[List of criteria that must be met for the enhancement to be considered accepted]

Additional Information

[Any other relevant information, such as links to related issues or pull requests]