Some ID3v2.4.0 frames such as text information frames support multiple strings
separated by the termination code of the character encoding. If the encoding
is $01 UTF-16 with BOM, all strings shall have the same byte order. In the
multi strings written by TagLib, all string elements of such a multi string
have a BOM. However, I have often seen tags where a BOM exists only at the
beginning, i.e. at the start of the first string. In such a case, TagLib will
only return a list with the first string and a second empty string. This
commit will detect such cases and parse the strings without BOM according to
the BOM of the first string.