Draft: Raise AmbiguousPrefixLookupError like Mercurial does
Mercurial passed from raising LookupError
to a more specific AmbiguousPrefixLookupError
in df0873ab5c14 (2018-04-13), which was released in v4.8 (2018-10-28).
This PR aligns hg-git behaviour to Mercurial and will, in time, allow to simplify a special handling code in TortoiseHg (see ba2dc2a07224 there).
Edited by Dan Villiom Podlaski Christiansen