Bug: General filter doesn't respect all field type specific filters

In the function edd_settings_sanitize, general filter edd_settings_sanitize use $value as one of the filter arguments. This ignores all field type specific filters 'edd_settings_sanitize_' . $type.

```
if ( $type ) {
    // Field type specific filter
    $input[$key] = apply_filters( 'edd_settings_sanitize_' . $type, $value, $key );
}
// General filter
$input[$key] = apply_filters( 'edd_settings_sanitize', $value, $key );
```

See issue #2532