bb-help-key throws error which causes page to not load when BBHelpClient is not present

[Blackbaud-StewartStephens]

When a page is opened as an addin with the addin=1 query string, BBHelpClient is not defined which causes the bb-help-key component to throw an error and prevents the page from loading. This can be worked around by hiding the bb-help-key component with an ngIf when the addin=1 query string is present, but maybe HelpWidgetService should check if BBHelpClient is defined before performing operations on it.