Affected: npm: fast-xml-parser

### Impact Application crashes with stack overflow when user use XML builder with `prserveOrder:true` for following or similar input

``` [{ 'foo': [ { 'bar': [{ '@_V': 'baz' }] } ] }] ```

Cause: `arrToStr` was not validating if the input is an array or a string and treating all non-array values as text content. _What kind of vulnerability is it? Who is impacted?_

### Patches Yes in 5.3.8

### Workarounds Use XML builder with `preserveOrder:false` or check the input data before passing to builder.

### References [_Are there any links users can visit to find out more?_](https://github.com/NaturalIntelligence/fast-xml-parser/pull/791)