Improve help messages when a plugin is installed but the connection is not configured

[e-gineer]

Describe the bug

If a plugin is installed, but not configured (e.g. no rss.spc file setup) then we should improve the error message.

Scenario

> .inspect rss
Error: Could not find connection or table called rss
> 

~/src $ 
~/src $ steampipe plugin install rss

rss                  [====================================================================] Already installed   

To update plugin which is already installed, please run steampipe plugin update rss

The first error message from the query should be changed from:

Error: Could not find connection or table called rss

to be:

Error: Could not find connection or table called rss. Is the plugin installed? Is the connection configured?

The second warning message should be changed from:

To update plugin which is already installed, please run steampipe plugin update rss

to be:

To update this plugin: steampipe plugin update rss
To update all plugins: steampipe plugin update --all