src/app/dashboards/azure.json: Update "How to add rows" description

The dashboard settings cog has moved to the upper right since Jordan
wrote the original text here.
src/app/dashboards/azure.json: Expand second row to fill 12 columns

There's no sense in setting up narrow text boxes when we have so much
space to work with.  We might as well fill the whole available width.
src/app/dashboards/azure.json: Rebalance initial row

There is more text in the "Introduction" section than in the "First
Step" section, so give it more width to avoid wasted space in the row.
src/app/dashboards/azure.json: Consolidate timestamp and filter rows

Newer versions of Kibana have Query and Filtering rows built into the
title bar, so we don't need to code them into our dashboard directly.
This commit drops our local Query bar and shifts the Filtering blurb
up to the same row as the timestamp blurb.  I've also used the 'title'
attribute instead of coding the title in Markdown, and updated the
filtering text to match the new title-bar implementation.