UniquePrefixMatcher: first check for an exact match.
UniquePrefixMatcher: first check for an exact match.

This allows short prefixes to be in the list, in order to reserve shortcuts.

mbedmicro/pyOCD,mbedmicro/pyOCD,mesheven/pyOCD,mesheven/pyOCD,mesheven/pyOCD,pyocd/pyOCD,pyocd/pyOCD,flit/pyOCD,flit/pyOCD,mbedmicro/pyOCD