Migrate project to vue-cli 3

[bugy]

At the moment webpack + babel + karma + plugins are used for frontend building and unit testing.
Unfortunately, it causes a lot of headache in configuration (many people use different combinations and versions, so it is extremely hard to find working solution anywhere). Especially it causes problems for unit testing (making everything built and tested properly is not trivial).
Another problem is bundle size. At the moment, Script server has almost 1Mb for the index page (600Kb js, 200Kb css, and everything else).

To solve these problems and make frontend infrastructure more lightweight, it makes sense to migrate to vue-cli, which uses predefined set of tools and plugins