Add user profile and avatar upload feature

web/backend/Database/Database.Migrations/scripts/01-schema/18-UserAvatar.sql

@@ -0,0 +1,43 @@
+CREATE TABLE dbo.UserAvatar
+(
+    UserAvatarID  UNIQUEIDENTIFIER
+        CONSTRAINT DF_UserAvatarID DEFAULT NEWID(),
+
+    UserProfileID UNIQUEIDENTIFIER NOT NULL,
+
+    PhotoID       UNIQUEIDENTIFIER NOT NULL,
+
+    ValidFrom     DATETIME2(3)     NOT NULL
+        CONSTRAINT DF_UserAvatar_ValidFrom DEFAULT SYSUTCDATETIME(),
+
+    ValidTo       DATETIME2(3)     NULL, -- NULL = currently active
+
+    RowVersion    ROWVERSION,
+
+    CONSTRAINT PK_UserAvatar PRIMARY KEY (UserAvatarID),
+
+    CONSTRAINT FK_UserAvatar_UserProfile
+        FOREIGN KEY (UserProfileID)
+            REFERENCES dbo.UserProfile (UserProfileID)
+            ON DELETE CASCADE,
+
+    CONSTRAINT FK_UserAvatar_Photo
+        FOREIGN KEY (PhotoID)
+            REFERENCES dbo.Photo (PhotoID)
+            ON DELETE NO ACTION
+            ON UPDATE NO ACTION,
+
+    CONSTRAINT CK_UserAvatar_ValidRange
+        CHECK (ValidTo IS NULL OR ValidTo > ValidFrom)
+);
+
+-- At most one active avatar per profile
+CREATE UNIQUE NONCLUSTERED INDEX UX_UserAvatar_ActiveOne
+    ON dbo.UserAvatar (UserProfileID)
+    WHERE ValidTo IS NULL;
+
+CREATE NONCLUSTERED INDEX IX_UserAvatar_Photo
+    ON dbo.UserAvatar (PhotoID);
+
+CREATE NONCLUSTERED INDEX ix_UserAvatar_Profile
+    ON dbo.UserAvatar (UserProfileID)