Toolkit: moved front end cli scripts to separate package and introduced very early version of plugin tools

* Move cli to grafana-toolkit

* Moving packages, fixing ts

* Add basics of plugin build task

* Add toolkit build task

* Circle - use node 10 for test-frontend

* Prettier fix

* First attempt for having shared tsconfig for plugins

* Add enzyme as peer depencency

* Do not expose internal commands when using toolkit from npm package

* Introduce plugin linting

* Fix missing file

* Fix shim extenstion

* Remove rollup typings

* Add tslint as dependency

* Toolkit - use the same versions of enzyme and tslint as core does

* Remove include property from plugin tsconfig

* Take failed suites into consideration when tests failed

* Set ts-jest preset for jest

* Cleanup tsconfig.plugins

* Add plugin:test task

* Rename file causing build failute

* Fixing those missed renames

* Add ts as peer dependency

* Remove enzyme dependency and tweak test plugin task

* Allow jest options overrides via package.json config

* Improvements

* Remove rollup node packages

* TMP : Fix ts errors when linked

* use local tslint if it exists

* support coverage commands

* Fix merge

* fix build

* Some minors

* Make jest pass when no tests discovered