Improve UI of Activate button in Add plugins page

[truongwp]

Should use button-primary class for Activate button in Add plugins page (like after installing plugin)

[adamsilverstein]

@truongwp Thanks for opening the ticket and adding a patch.

If several plugins are activated, there might be several buttons with the button-primary class applied at once. Do you think this might be an issue for screen readers or visual focus?

The primary class is usually added to indicate "this is the primary action on this screen" - I'm not sure that applies to 'Activate'.

[swissspidy]

IIRC we didn't add the primary class there on purpose because it's not the primary action on that screen. We added it for plugins that are being installed through Shiny Updates (Install -> Installing... -> Installed -> Activate, where Activate will be primary).

[truongwp]

Thanks for your explanation. I understood. There is a visual focus problem if there are many plugins is installed but not activated.

[Hareesh Pillai]

As per the above comments, it is intentionally built this way.
Adding the close keyword.