Add Additional Config File Loading

[Jdubrick]

Description

This PR adds the ability to load an additional configuration file alongside the RCS_CONFIG_FILE. This change currently supports the RHDH config map responsible for containing OLS plugin information, but can be extended to any additional configuration files. The file can be loaded and referenced similar to RCS through the RHDH_CONFIG_FILE environment variable.

The proposed change will grab all OLS related data and attempt to add providers defined in RHDH to RCS. These providers can then be used when hitting the /query endpoint.

You can find a demo overview of this change here: https://drive.google.com/file/d/1XDWqnSA7-Mz5hppiDAgDcIoYfNou3Tfn/view?usp=sharing

Type of change

• Refactor
• New feature
• Bug fix
• CVE fix
• Optimization
• Documentation Update
• Configuration Update
• Bump-up dependent library
• Bump-up library or tool used for development (does not change the final image)
• CI configuration change
• Konflux configuration change

Related Tickets & Documents

• Related Issue [RFE] Allow Additional Configuration Files #335
• Closes [RFE] Allow Additional Configuration Files #335
• JIRA https://issues.redhat.com/browse/RHDHPAI-528

Checklist before requesting a review

• I have performed a self-review of my code.
• PR has passed all pre-merge test jobs.
• If it is a core feature, I have added thorough tests.

Testing

• Please provide detailed steps to perform tests related to this code change.
• How were the fix/results from this change verified? Please provide relevant screenshots or results.

[tisnik]

it look ok, but I need some time to check it. Sorry!

[tisnik]

it looks ok!