API: Add updatedAt to api/users/:id (#19004)

* API: Add `updatedAt` to api/users/:id

This adds the timestamp of when a particular user was last updated to
the `api/users/:id` endpoint.

This helps our administrators understand when was the user information last
updated. Particularly when it comes from external systems e.g. LDAP

pkg/models/user.go

@@ -215,16 +215,17 @@ func (user *SignedInUser) IsRealUser() bool {
 }
 
 type UserProfileDTO struct {
-	Id             int64    `json:"id"`
-	Email          string   `json:"email"`
-	Name           string   `json:"name"`
-	Login          string   `json:"login"`
-	Theme          string   `json:"theme"`
-	OrgId          int64    `json:"orgId"`
-	IsGrafanaAdmin bool     `json:"isGrafanaAdmin"`
-	IsDisabled     bool     `json:"isDisabled"`
-	IsExternal     bool     `json:"isExternal"`
-	AuthLabels     []string `json:"authLabels"`
+	Id             int64     `json:"id"`
+	Email          string    `json:"email"`
+	Name           string    `json:"name"`
+	Login          string    `json:"login"`
+	Theme          string    `json:"theme"`
+	OrgId          int64     `json:"orgId"`
+	IsGrafanaAdmin bool      `json:"isGrafanaAdmin"`
+	IsDisabled     bool      `json:"isDisabled"`
+	IsExternal     bool      `json:"isExternal"`
+	AuthLabels     []string  `json:"authLabels"`
+	UpdatedAt      time.Time `json:"updatedAt"`
 }
 
 type UserSearchHitDTO struct {