I thought about a way to bulk install multiple plugins through the webinterface. To my knowledge, that is already possible by using the CLI, but I think adding it to the "Advanced" tab on the plugin manager is more convenient for people.

You could install plugins like

ant:1.13
credentials:1074.v60e6c29b_b_44b_
credentials-binding:1.27.1
...

which downloads the plugins from the Jenkins plugin repository. I thought about the format
<artifactId>:<version> to use.

That would be a handy method to install a bunch of plugins in no time without selecting one by one thru the plugin manager.