fix(cockpit/process-instance): fix variable type not being editable

Regression demanded fix.
chore(webapps/modal): use angular-ui for dialogs

Instead on relying on the self-written and outdated modalDialog
directive,
we are using the angular-ui to open and interact with dialogs.

- migrate all dialogs and move them to external templates
- remove modalDialog directive

additional cleanup
- remove angular cookie dependency

Closes CAM-1150
fix(tasklist/ui): fix task menu positioning

- Menu is pulled to the left
- Delegate menu is only shown if colleagues to delegate to are
  present.

Closes CAM-1129
Merge branch 'master' of github.com:camunda/camunda-bpm-platform