Timetracking frontend v1.1

This is a checklist for a bunch of little things that didn't make it into 1.0, but can be implemented quickly.

• Break vue component into smaller components and bundle them
• Improve the help state UX to look like this: https://gitlab.com/gitlab-org/gitlab-ee/issues/985#note_16056031
• Create helpers for props existence checking https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/870#note_18534273
• Improve grammar of styles and props https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/870#note_18535214
• Write integration tests that distinguish between MR and Issues
• Replace the $.on event listeners
• Open an MR to backport infrastructure changes to CE
• Improve naming with show computed values (add 'State') and pretty computed values
• Be clear about using human values from the server vs client
• Consider & address the accessibility impact of only displaying the remaining time in a tooltip and the percentage of time spent in a colored meter.

MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/901/diffs