add passphrase generator

[0xFaul]

resolves #426

• Admin can choose which password generator to use (random or phrases).
• Admin can set minimum number of words, which is overridden by minLength requirement of policy if the phrase is too short.
• Generated phrases have the following style: Word-Word-Word3 where a random number is placed behind a random word in the phrase.
• Generated phrases always contain special chars (seperator -), a number, uppercase letters and lowercase letters, so any generated phrase will, given it satisfies the length requirement, satisfy every other requirement.

Uses https://www.eff.org/files/2016/07/18/eff_large_wordlist.txt as wordlist.

user view (e.g. password for share links):

admin settings view (admins can toggle the generation of phrases and specify minimum word count):

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