* Fix errors decrypted non-ascii vault vars
AnsibleVaultEncryptedUnicode was just using b"".decode()
instead of to_text() on the bytestrings returned from
vault.decrypt() and could cause errors on python2
if non-ascii since decode() defaults to ascii.
Use to_text() to default to decoding utf-8.
add intg and unit tests for value of vaulted vars
being non-ascii utf8
based on https://github.com/ansible/ansible/issues/37258Fixes#37258
* yamllint fixups
