Adds results table context

[havok2063]

This PR closes #39. It adds the column description as hover tooltips to the table, preserving the sorting functionality of the v-data-table. See https://vuetifyjs.com/en/components/data-tables/basics/#headers-slot and https://stackoverflow.com/questions/77082361/how-to-add-tooltip-to-datatable-header-in-vuetify-3.

It also adds a context help window that, on hover, opens a dialog modal window that explains what to do on this page. It also switches the column titles from the original database column name, to their display_name from the db_metadata table.