stream-clone: support streamv3 on the cli [hg bundle] We add support and test for this. The support is still experimental, so the various name and identifier will eventually need to be renamed when stream-v3 gets out of experimental.

stream-clone: add the `-exp` prefix to the bundle part We forget to do so in 58adcabc295f, however this is important to prevent "current" client to send incompatible version to future client.