[m_delete] Using the studentId as parameter to delete makes it very troublesome

[GZTan23]

Description

Having to key in each of the studentIds individually to delete them is very cumbersome. Also, the command is cleared even if there is an invalid studentId, requiring the user to retype all the Ids again

Recommendation

Using the indexes of the contacts in the list would be easier and if there is an invalid input, do not clear the terminal