feat(chain): Upgradability functionality (#2701)

* Adding nightly test for upgradability: checks that after proper number of epochs active protocol versoins match

* Pipe protocol version via epoch manager/runtime

* Working on weaving upgradable block headers

* Make updatable BlockHeader compile.

* Adding support for legacy communication protocl

* Fix up networking to use oldest backward compatible version

* Update sample genesis to use latest protocol, while adding marker for first backward compatible one

* Remove backward compatibility. Bring protocol version from epoch manager to client

* Adding database version for future migrations

* Update rocksdb to 0.14

* Adding migration and update sample json

* Fix merge conflict

* Make Block data structure upgradable

* Version tracking in the epoch manager

* Bump protocol version after merge

* Current protocol version in status request

* Bump 0.6.2 & use Box

* Move migration to the right place

* Fix up merge conflicts

* Fix comments

* Reset Cargo.lock to master

Co-authored-by: Alexander Skidanov <skidanov.alexander@gmail.com>

Author: ilblackdragon

Cargo.lock

@@ -17,7 +17,7 @@ lazy_static = "1.4"
 num-rational = "0.2.4"
 tracing = "0.1.13"
 
-borsh = "0.6.1"
+borsh = "0.6.2"
 
 near-chain-configs = { path = "../../core/chain-configs" }
 near-crypto = { path = "../../core/crypto" }