Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/build/docker/keycloak/README.md

@@ -0,0 +1,61 @@
+To use this keycloak image, we suggest you to use this configuration settings:
+
+- Enable Login With SAML 2.0: `true`
+- Enable Synchronizing SAML Accounts With AD/LDAP: `true`
+- Override SAML bind data with AD/LDAP information: `false`
+- Identity Provider Metadata URL: empty string
+- SAML SSO URL: `http://localhost:8484/auth/realms/mattermost/protocol/saml`
+- Identity Provider Issuer URL: `http://localhost:8484/auth/realms/mattermost`
+- Identity Provider Public Certificate: The file `keycloak.crt` in this same directory
+- Verify Signature: `true`
+- Service Provider Login URL: `http://localhost:8065/login/sso/saml`
+- Service Provider Identifier: `http://localhost:8065/login/sso/saml`
+- Enable Encryption: `false`
+- Sign Request: `false`
+- Email Attribute: `email`
+- Username Attribute: `username`
+- Id Attribute: `id`
+- First Name Attribute: `firstName`
+- Last Name Attribute: `lastName`
+
+or overwrite your SamleSettings section with this settings in your config.json file (if you are not using
+database configuration) and restart the server:
+
+```json
+    "SamlSettings": {
+        "Enable": true,
+        "EnableSyncWithLdap": true,
+        "EnableSyncWithLdapIncludeAuth": false,
+        "IgnoreGuestsLdapSync": false,
+        "Verify": true,
+        "Encrypt": false,
+        "SignRequest": false,
+        "IdpUrl": "http://localhost:8484/auth/realms/mattermost/protocol/saml",
+        "IdpDescriptorUrl": "http://localhost:8484/auth/realms/mattermost",
+        "IdpMetadataUrl": "",
+        "ServiceProviderIdentifier": "http://localhost:8065/login/sso/saml",
+        "AssertionConsumerServiceURL": "http://localhost:8065/login/sso/saml",
+        "SignatureAlgorithm": "RSAwithSHA1",
+        "CanonicalAlgorithm": "Canonical1.0",
+        "ScopingIDPProviderId": "",
+        "ScopingIDPName": "",
+        "IdpCertificateFile": "saml-idp.crt",
+        "PublicCertificateFile": "",
+        "PrivateKeyFile": "",
+        "IdAttribute": "id",
+        "GuestAttribute": "",
+        "EnableAdminAttribute": false,
+        "AdminAttribute": "",
+        "FirstNameAttribute": "firstName",
+        "LastNameAttribute": "lastName",
+        "EmailAttribute": "email",
+        "UsernameAttribute": "username",
+        "NicknameAttribute": "",
+        "LocaleAttribute": "",
+        "PositionAttribute": "",
+        "LoginButtonText": "SAML",
+        "LoginButtonColor": "#34a28b",
+        "LoginButtonBorderColor": "#2389D7",
+        "LoginButtonTextColor": "#ffffff"
+    },
+```

server/build/docker/keycloak/keycloak.crt

@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----