[reference][configuration][security]Added key_length for pbkdf2 encoder
[Config] Complete security encoder in full default configuration

Added bcrypt and plaintext encoder
feature #4369 [reference][configuration][security]Added key_length for pbkdf2 encoder (Guillaume-Rossignol)

This PR was merged into the 2.3 branch.

Discussion
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[reference][configuration][security]Added key_length for pbkdf2 encoder

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | >=2.2
| Fixed tickets | -

Commits
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730dbb8 [Config] Complete security encoder in full default configuration
4b9a885 [reference][configuration][security]Added key_length for pbkdf2 encoder