Make intArrayToString symmetric to intArrayFromString

[juj]

We probably would want the following two invariants to hold for all valid inputs:

intArrayToString(intArrayFromString(someStringContainingNonBasicMultilingualPlaneUnicodeCharacters)) == someStringContainingNonBasicMultilingualPlaneUnicodeCharacters
intArrayFromString(intArrayToString(someArrayContainingAValidUTF8EncodedString)) == someArrayContainingAValidUTF8EncodedString

Currently reading the implementation of intArrayToString(), this is not the case. The implementation of intArrayFromString() looks good.

Currently the PR #5296 is touching this area, so should tend to this only after that PR lands.

[stale]

This issue has been automatically marked as stale because there has been no activity in the past 2 years. It will be closed automatically if no further activity occurs in the next 7 days. Feel free to re-open at any time if this issue is still relevant.