How to set a global error message for required fields in all subschemas

Hello, thanks for the library!

My schema looks like:
```js
{
if: {
properties: {
fieldType: {
const: 'field1',
},
},
required: ['fieldType'],
},
then: {
$ref: '#/definitions/customDefinition',
required: ['field1'],
errorMessage: {
required: 'Required',
},
},
else: {
$ref: '#/definitions/customDefinition',
required: ['field2'],
errorMessage: {
required: 'Required',
},
},
definitions: {
customDefinition: {
type: 'object',
properties: { date: { format: 'date' } },
required: ['date'],
errorMessage: {
properties: { date: 'Custom error message' },
required: 'Required',
},
},
},
errorMessage: {
required: 'Required',
},
};
```
Now I need to copy-paste
```js
errorMessage: {
required: 'Required',
},
```
in each subschema.

Is there an ability to set a global error message for required fields?