* Update Nimbus EVM code to use the latest nim-evmc which is now on EVMC v12.1.0
* Fix copyright.
* Fix tests.
* Update to use FkLatest.
* Fix copyright and update test helper.
* renamed nimbus folder to execution_chain
* Renamed "nimbus" references to "execution_chain"
* fixed wrongly changed http reference
* delete snap types file given that it was deleted before this PR merge
* missing 'execution_chain' replacement
---------
Co-authored-by: pmmiranda <pedro.miranda@nimbus.team>