Coerce the default parameter value when the parameter is no longer multi-select (#44690)

frontend/src/metabase-lib/v1/parameters/utils/operators.ts

...src/metabase-lib/v1/parameters/utils/parameter-parsing.ts

...se-lib/v1/parameters/utils/parameter-parsing.unit.spec.js

.../src/metabase-lib/v1/parameters/utils/parameter-values.js

frontend/src/metabase-types/store/mocks/dashboard.ts

frontend/src/metabase/dashboard/actions/parameters.ts

...nd/src/metabase/dashboard/actions/parameters.unit.spec.js

...nd/src/metabase/dashboard/actions/parameters.unit.spec.ts

...meters/components/ParameterSettings/ParameterSettings.tsx

frontend/src/metabase/parameters/utils/dashboards.ts