Add readonly label to console view

[bputt]

When using the node.sql.read_only config setting, it'd be beneficial to users who use the console view to let them know that they can only issue read only statements.

In our case, we have X number of master nodes with the node.sql.read_only: true and X number of ingest nodes with the node.sql.read_only: false.

[joemoe]

hi @bputt, thanks. i added this to our backlog. will let you know when there is further discussion happening. at the moment i can't give you an eta.