smith-members (!217)

* rebase: update metadata.scale

* review: replace `expect` by `if let Some`

* review: lost membership is to be handled by `OnMembershipEventHandler`

* feat(smith-members): review: docstring

* feat(smith-members): review: auteur

* fix(smith-members): test

* clean(smith-members): dead code

* feat(smith-members): disable certification replay

* refac(smith-members): prefix "on_" for handlers

* fix(smith-members): clippy again

* fix(smith-members): clippy

* feat(smith-members): benchmarks

* fix(smith-members): clippy for benchmarking

* refac(smith-members): u32 / usize

* refac(smith-members): cleaner code for smith invitation

* refac(smith-members): wrong TODO

* refac(smith-members): SmithInactivityMaxDuration

* refac(smith-members): remove comment TODO

* refac(smith-members): authority-members OnBlacklistedMember is no more used

* refac(smith-members): authority-members OnRemovedMember is no more used

* fix(smith-members): remove some TODO

* refac(smith-members): remove Instance1 for WoT

* refac(smith-members): remove IsSubWoT

* test(smith-members): non-applicable tests

* test(smith-members): test_revoke_idty

* test(smith-members): test_smith_member_can_revoke_its_idty

* test(smith-members): change_owner_key

* feat(smith-members): replace smith-wot by smith-members

* feat(smith-members): only online smiths can invite/certify other smiths

* feat(smith-members): only WoT members can be invited

* feat(smith-members): check IsWoTMember

* feat(smith-members): refac error names + fix cert on excluded

* feat(smith-members): events

* feat(smith-members): clippy

* feat(smith-members): refact: constants

* feat(smith-members): max stock of certifications per smith

* feat(smith-members): smith account can be excluded, not deleted

* feat(smith-members): refact: renaming

* feat(smith-members): refact: provide_is_member

* feat(smith-members): refact: check_* and do_* functions

* feat(smith-members): remove CertsByReceiver (all in Smiths)

* feat(smith-members): weird things

* feat(smith-members): blacklisting stub

* feat(smith-members): smith expires_on

* feat(smith-members): remove Counted

* feat(smith-members): accept_invitation

* feat(smith-members): invite_smith + certify