Remove manifest init step from network bootstrap workflow

[Stefan-Ethernal]

Description

Changelog:

• manifest command has been removed in favour of genesis command.
• premine-validators flag became redundant and is removed. Validators are premined using --premine as it is done with all the other accounts.
• rootchain init-contracts command is renamed into rootchain deploy, as it is shorter and enough self-explanatory.
• rootchain deploy instead of manifest, expects genesis file. It's absolute path is provided using --genesis flag.
• --tracker-start-blocks is removed as the event tracker configuration is now populated automatically into the genesis.json configuration as part of rootchain deployment.
• sequence of commands is changed: now the genesis command must be run before the rootchain deploy. Exact sequence is documented here.
• updated README files.

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Breaking changes

Genesis configuration has changed.

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

[Stefan-Ethernal]

cc @gatsbyz, @praetoriansentry, @DannyS03 to follow this PR, as it is going to affect both documentation and deployment procedure.

[vcastellm]

[goran-ethernal]

We say goodbye to a not so dear friend. He will not be missed 😛 .

Good job! 💯