Allow uppercase characters for lookup table test lookup

[grotlue]

Fixes: #14373

Description

The test look up for look up tables would manually override uppercase characters to lowercase.
This has be removed in this PR in order to allow looking up keys with uppercase characters.

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[gally47]

LGTM.