BUG: Fix crash instantiating ctkDICOMBrowser

[jamesobutler]

Following up to #973, this makes changes for ctkDICOMBrowser to not crash on initialization. @lassoan Would you like to make the additional DICOM related changes here now that the "Copy" import mode wouldn't be used? I'm a user that does not do any DICOM work so I do not know what would be appropriate behavior.

[jcfr]

Since ctkFileDialog (see [1]) already has an ivar called UsingNativeDialog, what about adding a convenience getter called ctkFileDialog::isUsingNativeDialog() ? Or would that be overkill ?

[1]

CTK/Libs/Widgets/ctkFileDialog.cpp

Line 54 in c4f1eee

bool UsingNativeDialog;

[jamesobutler]

Since ctkFileDialog (see [1]) already has an ivar called UsingNativeDialog, what about adding a convenience getter called ctkFileDialog::isUsingNativeDialog() ? Or would that be overkill ?

Doesn't matter to me. If you think ivar's need a method associated with them instead of getting them directly, I could change it.

[jcfr]

@jamesobutler I just fixed up the commit message prefix to be STYLE: instead of STYL:E. To easily catch this type of issue in the future, I also enabled the commitcheck GitHub app like we have in Slicer.

Regex is the same one ... (BUG|COMP|DOC|ENH|PERF|STYLE)\: \w+

[jcfr]

Also just added the following check as required ...

[jcfr]

Doesn't matter to me. If you think ivar's need a method associated with them instead of getting them directly, I could change it.

If we need to check for the status of the widget in application code, we may want to revisit. In the meantime, no need for it.