`discourse-common` was created in the past to share logic between the
'wizard' app and the main 'discourse' app. Since then, the wizard has
been consolidated into the main app, so the separation of
`discourse-common` is no longer useful.
This commit moves `discourse-common/(lib|utils)/*` into
`discourse/lib/*`, adds shims for the imports, and updates existing
uses in core.
Some reports, like the Web Crawler User Agents report, have very long strings that need to be truncated when displayed. However, there is no way to see the full value without exporting the report or inspecting the elements using dev tools. This PR set a `title` attribute with the full value to the reports `<td>` elements so that the full value is shown on hover.
