create MLZ configuration storage accounts with lowercase names

[glennmusa]

Description

• refactors generate_names.sh to make storage account names with lowercase alphanumeric names
• attempts to make makes resource-specific names easier to find and modify
• uses the first octet in a subscription ID to make a randomish_identifier instead of using the full GUID.

Issue reference

The issue this PR will close: #215

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles or validates correctly
• BASH scripts have been validated using shellcheck
• All tests pass (manual and automated)
• The documentation is updated to cover any new or changed features
• Markdown files have been linted using the recommended linter. (See .vscode/extensions.json.)
• Relevant issues are linked to this PR

[brooke-hamilton]

I deployed this with a big upper case deployment name. 👍