Option to disable vue-cli plugins through vue.config.js

[franciscolourenco]

What problem does this feature solve?

I have a project with multiple entry files and multiple vue.config.js, or a dynamic vue.config.js. Depending on the entry or target I would like to enable/disable certain vue-cli plugins.

What does the proposed API look like?

config.disablePlugins = []

[LinusBorg]

I pushed a PR for this. However I chose to solve this through a command line flag rather than an option in the config file as that is much more flexible, solving use cases like #3830 as well.