Normalize names

Created function for normalizing a vector of names in two steps:

I. Cleaning each string
   1. convert to all lower 
   2. convert accented characters (é) to their alphabetical counterparts (
   3. drop punctuation marks ("-")
   4. replace empty names by 'anon'

II. Splitting it into first name, last name and any remaining characters

Example:

```
names <- d$full_name[c(4,11,94,2470)] #where d is the output of merge_all_parties_and_years.R
names #INPUT
normalize_names(names) #OUTPUT
```

INPUT

| | 
 -------------
|Charles-Antoine Allain |
|Stéphane Allard |
|Charles E. Beaudoin|


OUTPUT

clean_full_name | last_name | first_name | remaining
------------- | ------------- | ------------- | -------------
charlesantoine allain    | allain | charlesantoine |
stephane allard |   allard   |    stephane |
 charles e beaudoin | beaudoin  |      charles | e
anon anon  |          anon | anon |