Viewer and configurator tiny fixes

[ryantrem]

1. The default viewer annotation UI does not show up if the innerHTML is white space only (e.g. code formatting). It seems this is just how slots work with html custom elements, but this is not how we want the viewer annotations to work. This change just sets the innerHTML to empty string if it is only white space so the default annotation UI still shows up (e.g. it is not replaced by html white space).
2. Changed the help icon in the Viewer Configurator based on bug bash feedback.
   

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