Monolithic duct solve

[moosebuild]

Imported from https://github.inl.gov/ncrc/subchannel/issues/64 : @moose-ncrc created issue at Jun 23, 2022 08:24AM MST:

In GitLab by @tanoret on Jun 23, 2022, 09:24

Description of the enhancement

The thermal solution in the duct system needs to be monolithically coupled to the subchannel equations (regarding NEAMS-M2 milestone specifications).

Rationale for the enhancement

For strong transient thermal couplings and using large time steps, the current methodology based on Picard iterations may be non-convergent.

Identified impact

Internal object changes.