fix: implement Amino serialization for x/authz and x/feegrant (cosmos…

…#11224)

* fix: Add RegisterLegacyAminoCodec for authz/feegrant

* add module name

* Fix GetSignByes, add tests

* removed module names from registered messages to match other modules

* added interfaces and concrete types registration

* unseal amino instances to allow external grant and authorization registration

* fixed messages tests

* allow to register external types into authz modulecdc

* use legacy.Cdc instead of ModuleCdc inside x/authz

* move the legacy.Cdc initialization outside init function

* added serialization docs

* Update docs/core/encoding.md

Co-authored-by: Amaury <1293565+amaurym@users.noreply.github.com>

* added the Ledger specification

* fixed tests

Co-authored-by: Amaury M <1293565+amaurym@users.noreply.github.com>