OAuth: Allow assigning Server Admin (#54780)

* extract errors to errors file

* implement oauth server admin assignment

* add server admin tests

* deduplicate autoAssignOrgRole

* deduplicate strict setting

* deduplicate strict setting

* add support for generic oauth

* add role attribute strict support for generic oauth

* add support for github/gitlab

* assignGrafanaAdmin option is here to stay

* unify similar errors

* add config option

* add okta server admin mapping

* remove never used Company attribute

* unify generic oauth role extract with other methods

* case insensitive role match as in azure

* add ini settings

* add server admin to devenv

* remove duplicate fields

* add documentation to oauth

* fix titlecase test

* implement doc feedback

pkg/api/login_oauth.go

@@ -263,14 +263,15 @@ func (hs *HTTPServer) buildExternalUserInfo(token *oauth2.Token, userInfo *socia
 	oauthLogger.Debug("Building external user info from OAuth user info")
 
 	extUser := &models.ExternalUserInfo{
-		AuthModule: fmt.Sprintf("oauth_%s", name),
-		OAuthToken: token,
-		AuthId:     userInfo.Id,
-		Name:       userInfo.Name,
-		Login:      userInfo.Login,
-		Email:      userInfo.Email,
-		OrgRoles:   map[int64]org.RoleType{},
-		Groups:     userInfo.Groups,
+		AuthModule:     fmt.Sprintf("oauth_%s", name),
+		OAuthToken:     token,
+		AuthId:         userInfo.Id,
+		Name:           userInfo.Name,
+		Login:          userInfo.Login,
+		Email:          userInfo.Email,
+		OrgRoles:       map[int64]org.RoleType{},
+		Groups:         userInfo.Groups,
+		IsGrafanaAdmin: userInfo.IsGrafanaAdmin,
 	}
 
 	if userInfo.Role != "" && !hs.Cfg.OAuthSkipOrgRoleUpdateSync {