* PLT-3073: Implement SAML/Okta Server side (EE) (#3422)

* PLT-3137 Support for SAML configuration

* PLT-3410 SAML Database Store

* PLT-3411 CLI to add Identity Provider Certificate and Service Provider Private Key

* PLT-3409 SAML Interface for EE

* PLT-3139 Handle SAML authentication server side

* Add localization messages

* PLT-3443 SAML Obtain SP metadata

* PLT-3142 Login & Switch to/from SAML

* Remove Certs for Database & Clean SAML Request

* Make required Username, FirstName and LastName

* PLT-3140 Add SAML to System Console (#3476)

* PLT-3140 Add SAML to System Console

* Move web_client functions to client.jsx

* Fix issues found by PM

* update package.json mattermost driver

* Fix text messages for SAML

Improving help text margins

Updating changes for get link and create post files

Fixing icon for select team screen

Fixing styles for select team button

Adding improvements to posts UI

Adding improvement to post layout

Updating changes for post controls

Updating z-index for sidebar--right

Updating help text position

Fixing code for posts

Fixing css for post view

Pushing improvements for posts view

Updating changes for post view

Updating post layout

Fixing system time css

Updating header for system posts

Updating post css

Removing opacity and changing color for system messages

Simplifying root post and system post behaviour

Removing images from compact view

Updating help text for display

Updating embed preview text for advanced option

PLT-3490 - Fixing RHS issue on Edge

* Change client-side max file size limit

It now relies on the value set in config.json.
Re-enable and tweak the max file size setting in system console.

* Update file upload error message

* Update custom emoji help text

* Update en.json

* Reorganized Backstage code to use a view controller and separated it from integrations code

* Renamed InstalledIntegrations component to BackstageList

* Added EmojiList page

* Added AddEmoji page

* Added custom emoji to autocomplete and text formatter

* Moved system emoji to EmojiStore

* Stopped trying to get emoji before logging in

* Rerender posts when emojis change

* Fixed submit handler on backstage pages to properly support enter

* Removed debugging code

* Updated javascript driver

* Fixed unit tests

* Fixed backstage routes

* Added clientside validation to prevent users from creating an emoji with the same name as a system one

* Fixed AddEmoji page to properly redirect when an emoji is created successfully

* Fixed updating emoji list when an emoji is deleted

* Added type prop to BackstageList to properly support using a table for the list

* Added help text to EmojiList

* Fixed backstage on smaller screen sizes

* Disable custom emoji by default

* Improved restrictions on creating emojis

* Fixed non-admin users seeing the option to delete each other's emojis

* Fixing gofmt

* Fixed emoji unit tests

* Fixed trying to get emoji from the server when it's disabled

Fix RHS adding an unecessary preference store listener and increase preference store listener max to 25 (#3473)

* Update ldap sync interval help text

* Update en.json

The new autolinking regex matches it and it could be argued that the link is valid anyway.

* Added the ability to search users by their first/last name or nickname when using @mentions

* Changed @mention autocomplete to display a user's nickname

* Added Onboarding Changes to Select Team

* changed text by PM

* PLT-3456 AppErrors that are triggered before translations are loaded crash server or produce bad error messages.

* Fixing tests

Revert "Moved file attachments to be stored in data/channels instead of data/teams/ID/channels (#3416)" (#3461)

This reverts commit ed75dfc6.

* Ensured code theme saves properly

* Adding expand icon for RHS

Fixing errors

Adding back getTeamInviteLink with better functionality for mobile

Adding vertical align to post__link

Updating improvements for expand RHS stuff

* Improving transition on mobile

* Removing irrelevant changes