Revert "packages/cockroach: improve iam-database-restore script"

[mhrabovcin]

This reverts commit 0bcab68.

High-level description

The #4251 changed iam-database-restore script on a false assumption that database renames could be handled transactionally.

After consulting with CockroachDB https://forum.cockroachlabs.com/t/renaming-database-in-a-transaction/2397 I've confirmed that this is not the case and we need to revert to a previous restore script version.

Corresponding DC/OS tickets (obligatory)

These DC/OS JIRA ticket(s) must be updated (ideally closed) in the moment this PR lands:

• DCOS-48182 cockroach: confirm that database renames are transactional

Checklist for all PRs

• Added a comprehensible changelog entry to CHANGES.md or explain why this is not a user-facing change: this fixes a problem of unreleased version
• Included a test which will fail if code is reverted but test is not. If there is no test please explain here:
• Read the DC/OS contributing guidelines
• Followed relevant code rules Rules for Packages and Systemd

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[d2iq-mergebot]

@mesosphere-mergebot bump-ee

[d2iq-mergebot]

Enterprise Bump PR: mesosphere/dcos-enterprise/pull/4582

[mhrabovcin]

@mesosphere-mergebot label Ready For Review

[mhrabovcin]

@gpaul @jongiddy please have a look.

[gpaul]

Good work here - I'm glad you asked the cockroachdb folks.

[jongiddy]

Thanks Martin