MDL-45982: Implement displaying of non error messages from a provider.
MDL-46144 core_calendar:Fixed label linking in calendar
MDL-43347 grades: consistent interface for drop lowest setting
MDL-43347 grades: convert keep highest to text field
MDL-46229 badges: Fix missing additional names fields

Signed-off-by: Yuliya Bozhko <yuliya.bozhko@totaralms.com>
MDL-42393 calendar: Preventing open/close loop in events overlay
MDL-46208 cachestore_mongo: fixed invalid collection name use
MDL-41389 auth_db: added user_updated/created event triggers
MDL-46016 auth_shibboleth: updated misleading comment

Also generated a random string for the password field in case it is ever used.
MDL-46248 calendar: HTML validation check fails on add event screen (Backport of MDL-42869)
Automatically generated installer lang files
MDL-41389 auth_db: added unit tests for events
MDL-45596 roles: Escape filter value before using it in form field
MDL-46126 upgrade: fix bogus nulls in user.password before changing precission

Note: there is no need to deal with Oracle empty strings here
because only MySQL running in non-strict mode is affected.
MDL-45678 assignsubmission_comments: Improve performance for permissions checking
MDL-46231 Merge English strings from the en_fix language pack
MDL-19270 - Quiz graph - Fix reverse display of Hebrew legend text in RTL mode
MDL-43848 messages: do not display message content in popups

The user is not in control of when these popups show up and it
may not be appropiate to have part of this content display whilst
in the presence of other users.
MDL-45616 repositories: more clearly distinguish when we use source and when reference

Function repository::get_moodle_file() should always be called on packed reference and not on the source received from user.
Also added phpdocs to some other methods that were confusing source and reference
MDL-45616 repositories: use json encoding instead of serialization