Fix rollback command

[Raneet10]

Description

Refer:

• Remove block while executing rollback tendermint#34
• baseapp,store: fix rollback to previous versions cosmos-sdk#25

This PR fixes rollback command in heimdall and adds a --force flag to do a hard rollback (mostly useful for nodes stuck with a bad app hash).

Changes

• 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)
• Changes only for a subset of nodes

Checklist

• I have added at least 2 reviewer or the whole pos-v1 team
• I have added sufficient documentation in code
• I will be resolving comments - if any - by pushing each fix in a separate commit and linking the commit hash in the comment reply

Testing

• I have added unit tests
• I have added tests to CI
• I have tested this code manually on local environment
• I have tested this code manually on remote devnet using express-cli
• I have tested this code manually on mumbai or amoy
• I have created new e2e tests into express-cli

[marcello33]

As discussed, please check e2e test on completion.
Besides that, LGTM