Instrument some (art) logging to WireCellToolkit_module

[brettviren]

From time to time issues are generated vaguely "blaming" some failure on WC. Sometimes the blame is warranted but sometimes it is due to the last line in the (art) log being from WC without directly implicating WC. Either WC crashed or WC had no further logs messages and something downstream broke.

We should add a couple lines in WireCellToolkit_module or perhaps WCLS_tool which brackets the entry from art to WCT. This way when the crash is inside WCT (or not) it will be more apparent.