No validation for user's name

[nus-pe-bot]

No one's number consists of pure number(s) but there is no check

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_{[original: nus-cs2113-AY2021S2/pe-interim#1210] [original labels: severity.Low type.FunctionalityBug]}

[jonahtwl]

Team's Response

It is up to the user to enter meaningful names. In this case, we have allowed alphanumeric values as we do not discriminate the way a user may want to name their friends/borrowers.

Duplicate status (if any):

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