[PE-D][Tester E] Exception for invalid parameters for Add Tag Functionality not handled

[nus-se-bot]

Description

Invalid parameters (symbols in parameters) for add-t command not dealt with correctly.\ User would not be certain what went wrong based on the output of the app

Steps for reproducing

1. add-t 7 cca/CCA#chair
2. add-t 1 cca/Skating - chair

Expected Result

Exception thrown and depicted in app to prompt user to correct command input parameters

Actual Result

Exception thrown in log, not depicted in app.\ App still shows Command Result from previous command (step 1)

for reference: result from step 1

Error Output

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Labels: severity.Medium type.FunctionalityBug original: joytqt-1202/ped#2