Improve test_alternatives.sh script

[paulmoon]

Improvements:

• Create functions for each DM/TF/KRM provisioning resources
• Don't require the user to login if we can detect that valid creds exist
• Colorize the success and failure messages
• Use only one project instead of requiring 3 different projects
• Clean up the resources after provisioning resources
• Fix a few bugs here and there, like
  • cp -R alternatives/krm should be cp -R alternatives/krm/, and same for Terraform
  • Add 60s timeout for waiting for PubSubSubscription
• Change deployment name from d1 to deployment to be slightly more descriptive

If this PR looks good, I'll make similar changes to the other existing test_alternatives.sh script. This should make future test_alternatives.sh script better.

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[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for all the commit author(s) or Co-authors. If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.
In order to pass this check, please resolve this problem and then comment @googlebot I fixed it.. If the bot doesn't comment, it means it doesn't think anything has changed.

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[google-cla]

CLAs look good, thanks!

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[google-cla]

CLAs look good, thanks!

ℹ️ Googlers: Go here for more info.