FromGmailFilterNames removes the " OR " separators between elements in the gmail filters sender list.

NumSpace formats numeric values for readability by adding spaces every three digits.

Reverse is not utf8 compatible ..

Reverse2 reverses Reference: https://stackoverflow.com/questions/1752414/how-to-reverse-a-string-in-go.

Reverse3 reverses Reference: https://stackoverflow.com/a/1754209.

Reverse4 reverses combines the best from SO answers (Reverse2 and Reverse3).

Reverse5 returns a string with the bytes of s in reverse order.

ReverseRune returns a string with the runes of s in reverse order.

ToGmailFilterNames removes the " OR " separators between elements in the gmail filters sender list.