[MODERATION] organization blocking a user (#802)

- Resolves #476
- Follow up for: #540
- Ensure that the doer and blocked person cannot follow each other.
- Ensure that the block person cannot watch doer's repositories.
- Add unblock button to the blocked user list.
- Add blocked since information to the blocked user list.
- Add extra testing to moderation code.
- Blocked user will unwatch doer's owned repository upon blocking.
- Add flash messages to let the user know the block/unblock action was successful.
- Add "You haven't blocked any users" message.
- Add organization blocking a user.

Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/802
(cherry picked from commit 0505a10421)

tests/integration/api_user_follow_test.go

@@ -19,7 +19,7 @@ func TestAPIFollow(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
 	user1 := "user4"
-	user2 := "user1"
+	user2 := "user10"
 
 	session1 := loginUser(t, user1)
 	token1 := getTokenForLoggedInUser(t, session1, auth_model.AccessTokenScopeReadUser)