mainchain in Genesis Data not necessary on mainchain

[Phanco]

Expected behavior

When pre-register sidechain on genesis_assets.json. Only sidechain data is required and can pass verification

Actual behavior

The following error occured if channelDataSubstore , chainDataSubstore, outboxRootSubstore and chainValidatorsSubstore for mainchain not present

Error: If a chain account for another sidechain is present, then a chain account for the mainchain must be present, as well as the own chain account.

Steps to reproduce

n/a

Which version(s) does this affect? (Environment, OS, etc...)

v6.0.0-alpha.14

[Phanco]

Closing this task as it has been deprioritied