Add Ons page tabbing doesn't tab through each block correctly.

[andrewlimaza]

Describe the bug
When tabbing through the Add Ons page, it tabs through the featured image and title before moving onto the next Add On and skips over the "Install/Activate" button.

To Reproduce
Steps to reproduce the behavior:

1. Go to Memberships > Add Ons
2. Click on 'the screen, somewhere in between the list of Add Ons or after searching for an Add On.
3. Press tab to navigate through this page and see the error.

Screenshots
Here is a recording of using the tab button while in the Add Ons page. You can see here that the "Activate" or "Install" button is never in focus.

Expected behavior
The tabbing sequence should navigate to the "Install/Activate" button before moving onto the next Add On.

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only Paid Memberships Pro plugin is active.
• This bug happens with a default WordPress theme active, or Memberlite.
• I can reproduce this bug consistently using the steps above.