Check that either folding config or target fps is set

[LeahLS]

Prerequisites

None

Details

New behavior

There should be an error message early in the build flow if neither a folding config nor the target fps are specified in the build config. Therefore, checks could be added to ensure that either of them is always specified in the building config.

Motivation

When starting the build flow with neither a folding config nor a target fps set, a weird error at the hw ipgen step occurs saying that the name of the projects hasn't been set.

Parts of FINN affected

Transformation, FPGA Dataflow, Set Folding