[BugFix] - Case insensitive credentials

[montezdesousa]

1. Why?

   • User might want to specify their key names in uppercase

2. What?

   • Create uppercase alias in the Credentials model

3. Impact:

   • Locally ~/.openbb_platform/user_settings.json allows uppercase credential name
   • OpenBB Hub, same as above

4. Testing Done:

Local test (user_settings.json)

# Set an uppercase key such as BIZTOC_API_KEY -> biztoc_api_key
from openbb import obb
obb.user.credentials.show()

Hub test

# Set an uppercase credential here https://my.openbb.dev/app/platform/credentials
# Such as BIZTOC_API_KEY -> biztoc_api_key
%env OPENBB_HUB_BACKEND=https://payments.openbb.dev
from openbb import obb
obb.account.login(pat="...")
obb.user.credentials.show()