fix(cache): force keys to lowercase

[braddf]

Pull Request

Description

Forces all cache keys to lowercase by calling .lower() on the key_builder output, ensuring cache hits regardless of the case of query parameter values passed by the client.
Existing hardcoded warm keys are already lowercase so read/write consistency is maintained.
The @cache decorator uses key_builder for both lookup and store, so both paths are covered by this change.

Fixes #

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce.
Please also list any relevant details for your test configuration

• Locally

If your changes affect data processing, have you plotted any changes? i.e. have you done a quick sanity check?

• Yes

Checklist:

• My code follows OCF's coding style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked my code and corrected any misspellings

[peterdudfield]

I wonder if the tests are failing becasue the timezon 'Z' got moved down to a z, this might have to be updated in the test

[braddf]

Yeah I think def something like that with the datetime strings – right now we're only aware of the boolean attributes that are allowed to be in whatever case, so have just made it more specific for now.

[peterdudfield]

couldnt you do lower?

And then I think in one of the tests you need to use t (not T) and z( not Z)?