[FEA] Update bundle operator

[binliunls]

Is your feature request related to a problem? Please describe.
The current MONAI bundle inference operator is based the MONAI bundle parser. However in MONAI 1.2, the bundle workflow has been introduced into MONAI core for a more convinent and flexible downstream use case. Therefore, I would like to see a new version of bundle inference operator to utilize the bundle workflow concept.

Describe the solution you'd like
A new MONAI bundle inference operator integrated with the bundle workflow pipeline.