test: ignore bytes lenght in message We should be storying floating point number as floating point number. So the size of the meta for fm0 format is going to be unstable. We cover them with a glob.

evolve: adapt to the new metadata storage Metadata are not stored as a "list" of (key, value) tuple instead of a binary blob. This adapt to ef880e28e56a in Mercurial.

debugobsstorestats: drop the average meta length Does not have much sense with the existence of multiple format with different meta storage. We drop it for now and will introduce and average markers length later.