* Use unittest2 test runner
Since upgrading to unittest2, the test runner prints the command line to
re-run a failed test - this however relies on actually using the
unittest2 command line runner.
Previously, test files were assigned numbers - with the unittest2
runner, tests are run using suite/category names instead, like so:
```
# run the Genesis suite
build/all_tests "Genesis::``
# run all tests with "blsMapG1" in the name
build/all_tests "blsMapG1*"
# run tests verbosely
build/all_tests -v
```
A reasonable follow-up here would be to review the suite names to make
them easier to run :)
* lint
* easier-to-compare test order
* bump unittest2 (also the repo)
* 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>
* Cleanup unneeded stateless and block witness code. Keeping MultiKeys which is used in the eth_getProofsByBlockNumber RPC endpoint which is needed for the Fluffy state network bridge.
* Rename generateWitness flag to collectWitnessData to better describe what the flag does. We only collect the keys of the touched accounts and storage slots but no block witness generation is supported for now.
* Move remaining stateless code into nimbus directory.
* Add vmstate parameter to ChainRef to fix test.
* Exclude *.in from check copyright year
---------
Co-authored-by: jangko <jangko128@gmail.com>
