Improve error handling

[CatalinaYepes]

For example, if by mistake the user assigns the wrong calculation_mode in the configuration file of the demos/hazard/ScenarioCase1, and indicates, for example, scenario_damage, the following error appears:

(openquake) ➜  ScenarioCase1: ✗ oq engine --run job.ini
[2024-06-05 18:40:13 #5 INFO] usuario@c.local running ~/oq-engine/demos/hazard/ScenarioCase1/job.ini [--hc=None]
[2024-06-05 18:40:13 #5 INFO] Using engine version 3.21.0-gitbca2bf6ad0
[2024-06-05 18:40:14 #5 WARNING] Using 8 processpool workers
[2024-06-05 18:40:14 #5 INFO] Checksum of the inputs: 2365574846 (total size 1.39 KB)
[2024-06-05 18:40:14 #5 INFO] Running EventBasedCalculator with concurrent_tasks = 16
[2024-06-05 18:40:14 #5 INFO] Inferring the hazard grid
[2024-06-05 18:40:14 #5 INFO] Read N=168 hazard sites and L=2 hazard levels
Traceback (most recent call last):
  File "/Users/cye/openquake/bin/oq", line 8, in <module>
    sys.exit(oq())
             ^^^^
  File "/Users/cye/oq-engine/openquake/commands/__main__.py", line 48, in oq
    sap.run(commands, prog='oq')
  File "/Users/cye/oq-engine/openquake/baselib/sap.py", line 212, in run
    return _run(parser(funcdict, **parserkw), argv)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/cye/oq-engine/openquake/baselib/sap.py", line 203, in _run
    return func(**dic)
           ^^^^^^^^^^^
  File "/Users/cye/oq-engine/openquake/commands/engine.py", line 181, in main
    run_jobs(jobs)
  File "/Users/cye/oq-engine/openquake/engine/engine.py", line 418, in run_jobs
    run_calc(jobctx)
  File "/Users/cye/oq-engine/openquake/engine/engine.py", line 281, in run_calc
    calc.run(shutdown=True)
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 256, in run
    raise exc from None
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 244, in run
    self.pre_execute()
  File "/Users/cye/oq-engine/openquake/calculators/event_based_risk.py", line 345, in pre_execute
    super().pre_execute()
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 619, in pre_execute
    calc.run(remove=False)
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 256, in run
    raise exc from None
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 244, in run
    self.pre_execute()
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 629, in pre_execute
    self.read_inputs()
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 504, in read_inputs
    self._read_risk2()
  File "/Users/cye/oq-engine/openquake/calculators/base.py", line 911, in _read_risk2
    taxonomies = python3compat.decode(self.assetcol.tagcol.taxonomy[1:])
                                      ^^^^^^^^^^^^^
AttributeError: 'EventBasedCalculator' object has no attribute 'assetcol'

A clear error message should appear staying: A scenario_damage calculation requires as input file the exposure model, which is missing in the configuration file

And something similar for other parameters and calculation modes.