Move PVWatts Bifacial option from Advanced Parameters panel to System Parameters group

[cpaulgilman]

As bifacial module market share increases, as of SAM 2024.12.12, we are using bifacial modules as default for BTM commercial and FOM applications for Detailed PV configurations. We would like to to the same for PVWatts, but first need to move the bifacial input from the Advanced Parameters panel because it is hidden by default.

Also consider making this change for the online PVWatts calculator for consistency.

[janinefreeman]

Related to NatLabRockies/pysam#181