[Refresh] Add refresh button to center pane, nasa/mct#138

This adds a refresh button to the title area of the center pane. This triggers the existing Refresh Now action.

Also fixes an issue where certain updates reflected in the Browse area were not shown after the refresh; now, go straight to persistence and get the latest version of the object. This is the same behavior exhibited by switching Views back and forth in the View menu.

 Wrote or re-wrote unit tests (Y/N): Y
 Ran entire suite of unit tests successfully (Y/N): Y
 Verified bug fix with the described replication steps or verified the implementation meets the requirement cited (Y/N): Y
 Code coverage requirements satisfied (new code=80%, changed code=at least as high as existing) (Y/N): Y
 Code review date and attendees: Code review by pull request
 Describe potential impact on other areas of the code: Center pane views
 Describe any test prerequisites for this fix (e.g., restart the database): N/A
 For bugs marked "Regression - Yes", describe the cause of the regression: N/A
 Did you modify any pom.xml file? If yes, did you thoroughly document your changes and reasons? N