use MLZ_LOCATION instead of reserved term Location

[glennmusa]

Description

As noted in #138 , the UI will return 500's when trying to execute terraform because the environment variable Location is a reserved key. This change uses MLZ_LOCATION instead.

Issue reference

The issue this PR will close: #138

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