Error message for calling commands with zero modules/tutorials can be more descriptive

[marcus-ny]

Steps to reproduce:

1. Ensure no modules or tutorials
2. /allocate_team index/1 module/AX1101R tutorial/T01 team/redTeam

Output: The tutorial class with tutorial code T01 does not belong to the module with module code AX1101R

Since neither the tutorial nor the module exists, the message may not be indicative of the actual issue as it seems to state that these two do not match rather than the fact that they do not exist. However, the issue is very minor.