Retrieves an array of value from a form located by CSS or XPath and returns it to test.
Resumes test execution, so **should be used inside async function with `await`** operator.

```js
let inputs = await I.grabValueFromAll('//form/input');
```
@param {CodeceptJS.LocatorOrString} locator field located by label|name|CSS|XPath|strict locator.
@returns {Promise<string[]>} attribute value