[services] Tunnelbroker - Introduce validateUUIDv4 function

Summary:
This diff introduces validateUUIDv4 function that checks the validity of the generated UUIDs based on the regular expression.

Related linear task: ENG-1360

Test Plan: Tests from D4468

Reviewers: karol-bisztyga, palys-swm

Reviewed By: palys-swm

Subscribers: ashoat, palys-swm, Adrian, atul, karol-bisztyga, yayabosh

Differential Revision: https://phab.comm.dev/D4467