Create new Vue Router page for metrics builder

Description

As part of #228761 (closed) we should create new Vue Router page for the metrics builder.

This page would initially be empty and it would contain the component created at #228761 (closed)

Technical Description

• Builder page should be "stateless", all params entered by the user should be sync to the URL.
  • Two params are defined for now: "Time Range" and "Panel YML".
• Should we add View Router "Named Views"?
  • We have 2 main areas: Top Bar (contains date picker, ...) and Body Content.
    • Expanded Panel view may benefit later on!