calcs/risk/general:

Added a check to `parse_vulnerability_model` to display a useful error if a
vuln model specifies an IMT which is incompatible with the specified
`--hazard-output-id`.
tests/calcs/risk/general_test:

Added a test to exercise the incompatible IMTs validation check (between
hazard curves, specified as a `--hazard-output-id` and the IMTs in a vuln
model).