[MODERATION] user blocking

- Add the ability to block a user via their profile page.
- This will unstar their repositories and visa versa.
- Blocked users cannot create issues or pull requests on your the doer's repositories (mind that this is not the case for organizations).
- Blocked users cannot comment on the doer's opened issues or pull requests.
- Blocked users cannot add reactions to doer's comments.
- Blocked users cannot cause a notification trough mentioning the doer.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/540
(cherry picked from commit 687d852480)
(cherry picked from commit 0c32a4fde5)
(cherry picked from commit 1791130e3c)
(cherry picked from commit 37858b7e8f)
(cherry picked from commit a3e2bfd7e9)

models/user/user_test.go

@@ -449,13 +449,13 @@ func TestFollowUser(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 
 	testSuccess := func(followerID, followedID int64) {
-		assert.NoError(t, user_model.FollowUser(followerID, followedID))
+		assert.NoError(t, user_model.FollowUser(db.DefaultContext, followerID, followedID))
 		unittest.AssertExistsAndLoadBean(t, &user_model.Follow{UserID: followerID, FollowID: followedID})
 	}
 	testSuccess(4, 2)
 	testSuccess(5, 2)
 
-	assert.NoError(t, user_model.FollowUser(2, 2))
+	assert.NoError(t, user_model.FollowUser(db.DefaultContext, 2, 2))
 
 	unittest.CheckConsistencyFor(t, &user_model.User{})
 }
@@ -464,7 +464,7 @@ func TestUnfollowUser(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 
 	testSuccess := func(followerID, followedID int64) {
-		assert.NoError(t, user_model.UnfollowUser(followerID, followedID))
+		assert.NoError(t, user_model.UnfollowUser(db.DefaultContext, followerID, followedID))
 		unittest.AssertNotExistsBean(t, &user_model.Follow{UserID: followerID, FollowID: followedID})
 	}
 	testSuccess(4, 2)