* [frame/im-online] remove `external_addresses` from heartbeats
Users should use DHT for discovering new nodes. The reason for adding external addresses was
unstable work of authority discovery (see https://github.com/paritytech/substrate/issues/2719),
which is now stable. Hence we can safely remove `external_addresses`.
Refs https://github.com/paritytech/polkadot/issues/7181
* remove unused import
* run benchmark
* remove external_addresses from offchain NetworkState
* add missing fn to TestNetwork
* Revert "run benchmark"
This reverts commit a282042c2d6bf8bae2c383f6e2699c3fe2970a3d.
* update weights
* address @bkchr comments
* remove duplicate fn
* cleanup benchmarking.rs
* fix executor tests
* remove peer_id from hearbeat as well
https://github.com/paritytech/substrate/pull/14251#discussion_r1210887220
* remove MaxPeerDataEncodingSize
* change storage value type to `()`
https://github.com/paritytech/substrate/pull/14251#discussion_r1214268931
* scaffold storage migration
* no need to check the type actually
* remove unnecessary types from v0 mod
* add a test for migration
* expose Config types
+ pre_upgrade and post_upgrade working fn
* fix test
* replace dummy type with ConstU32
* add some comments to migration test
* fix comment
* respond to @bkchr comments
* use BoundedOpaqueNetworkState::default
intead of using default for each field