Add a graceful disconnect to CAD data in Catalog

[RTPL_AU]

In some cases when right clicking on dxf or dwg files to view their properties something may go wrong and the Properties window may take a while to open or not show any info when open.

It could be due to invalid geometry or any number of CADD related issues. 

Currently you can close the Properties window but then "Properties will be greyed out for any other CAD data source until Pro has decided to let go of the file and/or restart a process somewhere.

Please provide a button or a context menu entry to close any connection / hold, and/or restart the relevant process so that we can get on with real work.