[Discover] Share > Export modal falsely shows "unsaved state" treatment

[tsullivan]

When exporting CSV from Discover, users are getting a confusing warning message. The warning seems designed to let users know that if they copy the POST URL for Reporting CSV export, an upgrade to Kibana may somehow cause their copied URL to be broken.

There are a few issues here:

1. This warning shows up all the time, even when the work in Discover does NOT have unsaved changes
2. This warning shows up even if the user does not intend to copy the POST URL
3. The URL that gets copied has a version field. This means that future versions of Kibana should be able to parse the URL in a backwards-compatible way.
4. There is no reason for the "Generate CSV" button to be rendered in the warning color. That creates a report artifact, not something that needs compatibility with future versions.

Recommendations:

1. Do not show any warning text if the work in Discover doesn't have unsaved changes.
2. Decide how important it is to show that warning text. If we need to it when there are unsaved changes, just make it a tooltip that appears when the mouse hovers over the "Copy POST URL" button.
3. Always show the "Generate CSV" button in the primary action color (blue), not the warning color (yellow).
4. Follow through in the Dashboard app to make the Share > Export modal consistent (show the warning text as a tooltip, always show the "Generate" button in primary action color).

Screencast:

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[kevinsweet]

@tsullivan this is very clearly written/summarized thank you

Let's update the text in these 2 places and follow all recommendations as written. The tooltip can be above as it is today I just mocked this up quickly