display 0 fee value as number instead of N/A in transaction list

[SpaceSurfer1]

In transaction listing, when fee value is 0, number will be displayed instead of N/A.

Fixes #8286

Testing instructions

• Using a US merchant, assign wcpay-discount-100-off and refresh the client cache
• Perform a test purchase (any payment method)
• Check the transactions listing page and compare it to transaction details page

---

• Run npm run changelog to add a changelog file, choose patch to leave it empty if the change is not significant. You can add multiple changelog files in one PR by running this command a few times.
• Covered with tests (or have a good reason not to test in description ☝️)
• Tested on mobile (or does not apply)

Post merge

• Link to testing instructions from release testing doc following these instructions : Add link here / 'QA Testing Not Applicable'
• Add or update critical flows and testing instructions for critical flows, if applicable.
• Add what's changed (description, screenshot, demo videos etc.) to the release announcement post, if applicable.

[SpaceSurfer1]

Hi, @kalessil , @anu-rock , can you kindly review this PR? Thanks. 👍

[kalessil]

Thank you @SpaceSurfer1!

Overall looks good, a couple of things remaining:

• CI prompts we need a changelog entry, which can be added as per https://github.com/Automattic/woocommerce-payments/blob/develop/CONTRIBUTING.md#changelog-entries
• I actualized the branch and waiting for CI checks to complete (some of tests might need to be updated)

EDIT: the tests I was waiting for are green, so we only need a changelog entry here.