20240405.00

Log clearly when the initial parsing of a JSON object fails (#132)

* Split out root element parsing into a shared ParseJsonRoot; add better error logging.

* remove a couple of perhaps-overeager log lines; add a missing space to fix a typo.

* Properly initialize the tokener before use.

* Also, don't forget to free the tokener after use.

* respond to Leos review feedback

* fix build failure due to goto jumping over initialization