Function checkPhoneInput

checkPhoneInput(value: string): InputState
Checks a Pakistani mobile number while the user is typing. The 03XX prefix is checked as soon as it is complete. See InputState.
Parameters
- value: string
Returns InputState
Example
```
checkPhoneInput('0300 12');     // 'incomplete'
checkPhoneInput('0360');        // 'invalid' (prefix not allocated)
checkPhoneInput('03001234567'); // 'valid'
```
- Defined in input.ts:119