fix: edge case in-place-testnet states

[czarcas7ic]

Description

Closes: #XXXX

Killing a node, setting a halt height, and gracefully shutting down cause varying states of the block height across app/blockStore/state. This PR handles these states properly.

Additionally, there was an edge case where if prometheus was enabled, it would panic due to setting it a second time in testnetify. We don't actually need the metrics provider to match what the user wants in testnetify since this is just used temporarily while setting up the application, so we use the default config of instrumentation to prevent this panic from happening.

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
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
• added a changelog entry to CHANGELOG.md
• 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

All items are required. Please add a note if the item is not applicable and please add
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)