Added aggregated script for docker deployment and cosmos-sdk testing script

[chetanyb]

Description

1. Added aggregated docker devnet script reducing steps for local devnet deployment
2. Updated README to make use of aggregated docker_devnet.sh script
3. Added cosmos_release_heimdall.sh script for ease of testing for various commits with heimdall using matic-cli
4. Added detailed README for the new cosmos_release_heimdall.sh script

Changes

• Bugfix (non-breaking change that solves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)
• New test case for remote devnet

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

Cross repository changes

It should never be the case...

• This PR requires changes to bor
  • In case link the PR here:
• This PR requires changes to heimdall
  • In case link the PR here:

Testing

• 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

Manual tests

Please complete this section with the steps you performed if you ran manual tests for this functionality, otherwise delete it

Additional comments

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