Change update available tag to a button

[ArEyeses79]

When a row of plugins is shown they have tags such as 'by [author]' and 'Installed', as well as an 'Update Available' tag if the plugin was updatable.
This update available tag looks a lot like a button but is not clickable. It would be nice if this was a button that will update that plugin

(I've found the relevant code to check and it looks like it is intentionally a tag rather than a broken button; https://github.com/openplanet-nl/plugin-manager/blob/master/src/Interface/Controls/PluginTags.as#L15 )

[codecat]

I think instead of turning it into a button, we could try to make it look less like one, partly because that simplifies the problem of input handling, but also because it will be consistent everywhere else.