ci: move upgrade assure scripts to cmd and improve ci workflow

[cosmic-vagabond]

Description

What has Changed?

• move upgrade assure and upload snapshot scripts to cmd folder
• add makefile rules to build those script binaries
• updated upgrade assure README to reflect the new API
• updated upgrade assure script to include more independent steps to have more granular view of each step and CI can call them separately to reduce memory usage
• update CI workflow to add more steps in the software upgrade test process
• compile the resulting chain data into a snapshot file
• upload the new snapshot file to the R2 snapshots repository
• add CI cache for the snapshot retrieval process, it will download the new snapshot only if block height is different than the one already cached
• skip all the steps from snapshot retrieval to voting proposal for software upgrade if snapshot cache is still valid
• add both ~/.elys and ~/.elys2 to the cache as well
• unbond validator 2 power

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Author Checklist

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please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

Deployment Notes

Are there any specific considerations to take into account when deploying these changes? This may include new dependencies, scripts that need to be executed, or any aspects that can only be evaluated in a deployed environment.

Screenshots and Videos

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