Tracking issue: Projectfile import useability issues

[JoerivanEngelen]

This is a tracking issue to keep track of all the present useability issues with the projectfile import. The list will probably be expanded in the future. Feel free to add issues that should be added to the list in the comments.

• ybrahim and Moria import: fix hfb merging issue #1135
• ybrahim import: deal with empty wells #1134
• Projectfile: Read PST package data #1084
• Projectfile: Improve error message when number of stresses doesn't match number of data entries #1077
• Projectfile: Support loading boundary conditions with both a steady-state as well as transient timestamps #1073
• IPF associated reader not able to parse datetimes beyond the year 2261 #1163
• Well: Issues when importing steady-state from iMOD5 #1166
• Well: ipf files with the same name, but different folder, are grouped #1167
• River/Drain allocation: Option for negative layer missing #1177
• Modflow6Simulation.from_imod5_data does not work with constant values in PRJ #1323
• Modflow6Simulation.from_imod5_data does not work with HFB #1322