I have a character vector that looks like this:
 vector
 "Narcos: Mexico, Narcos, Narcos: Mexico"
 "V for Vendetta, Narcos: Mexico"
 "Criminal: France, Criminal UK, Criminal: France"
 "V for Vendetta"
 ...
what I want to do is to get rid of duplicate titles from for each row, where every title is separated by a comma:
 "Narcos: Mexico, Narcos"
 "V for Vendetta, Narcos: Mexico"
 "Criminal: France, Criminal UK"
 "V for Vendetta"
 ...
data
vector1 <- c("Narcos: Mexico, Narcos, Narcos: Mexico", "V for Vendetta, Narcos: Mexico", 
"Criminal: France, Criminal UK, Criminal: France", "V for Vendetta"
)