* db: add login attempt migrations
* db: add possibility to create login attempts
* db: add possibility to retrieve login attempt count per username
* auth: validation and update of login attempts for invalid credentials
If login attempt count for user authenticating is 5 or more the last 5 minutes
we temporarily block the user access to login
* db: add possibility to delete expired login attempts
* cleanup: Delete login attempts older than 10 minutes
The cleanup job are running continuously and triggering each 10 minute
* fix typo: rename consequent to consequent
* auth: enable login attempt validation for ldap logins
* auth: disable login attempts validation by configuration
Setting is named DisableLoginAttemptsValidation and is false by default
Config disable_login_attempts_validation is placed under security section
#7616
* auth: don't run cleanup of login attempts if feature is disabled
#7616
* auth: rename settings.go to ldap_settings.go
* auth: refactor AuthenticateUser
Extract grafana login, ldap login and login attemp validation together
with their tests to separate files.
Enables testing of many more aspects when authenticating a user.
#7616
* auth: rename login attempt validation to brute force login protection
Setting DisableLoginAttemptsValidation => DisableBruteForceLoginProtection
Configuration disable_login_attempts_validation => disable_brute_force_login_protection
#7616
At least in my Postgresql 9.6.5, the old syntax of capitalized queries doesn't work (Linux).<br>
Running with UTF-8 as standard encoding and the ` notations didn't work either, so removed those.
* use utf8mb4 character set for connections to mysql
* use utf8mb4 character set for tables, shorten varchar fields used in unique indexes
* migration type to update table character set
* update table character sets
* set charset for temp_user.status
* gofmt
