Config migration

[AlexandraRoatis]

Description

Automatically migrates the old kernel configurations as follows:

1. check if config/config.xml exists:
2. if no, it's already a new kernel and no changes are necessary;
3. if yes:
   i. read the file located at config/config.xml;
   ii. check the network id in the config and match it to the available networks: conquest, mainnet, mastery, or custom;
   iii. delete config/config.xml and config/genesis.json;
   iv. overwrite [network]/config/config.xml with the read configuration;
   v. set database, log and keystore to absolute path based on the location read from the old config.

Type of change

Insert x into the following checkboxes to confirm (eg. [x]):

• Bug fix.
• New feature.
• Enhancement.
• Unit test.
• Breaking change (a fix or feature that causes existing functionality to not work as expected).
• Requires documentation update.

Testing

Please describe the tests you used to validate this pull request. Provide any relevant details for test configurations as well as any instructions to reproduce these results.

• existing test suite
• updated tests for new behavior
• manual checks to verify that the configuration files get correctly copied and deleted, the absolute path to the keystore is added and the paths to the database and logs are set to absolute.

Verification

Insert x into the following checkboxes to confirm (eg. [x]):

• I have self-reviewed my own code and conformed to the style guidelines of this project.
• New and existing tests pass locally with my changes.
• I have added tests for my fix or feature.
• I have made appropriate changes to the corresponding documentation.
• My code generates no new warnings.
• Any dependent changes have been made.

[AionJayT]

LGTM