Discrepancy between svmbir and mbircone (keep updating)

[dyang37]

This issue records the discrepancies between svmbir and mbircone.
Once these get extensively tested, we'll make necessary changes in svmbir to align the two interfaces.

• constant in auto_sigma_p:
  • svmbir: 1.0 * auto_sigma_prior(sino, delta_channel, sharpness)
  • mbircone: 2.0 * auto_sigma_prior(sino, magnification, delta_pixel_detector, sharpness)
• default value of snr_db: 30 dB in svmbir, 40 dB in mbircone.
• In mbircone recon(), we need to add geometry argument and default it to cone.