[misc] add oci auth for up, ip, and rp

[slin1237]

What type of PR is this?

/kind feature
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What this PR does / why we need it:

multi cloud support auth module for oci

Which issue(s) this PR fixes:

#100 #101 #102 #103 #94

Fixes #
#100 #101 #102 #103

Special notes for your reviewer:

Does this PR introduce a user-facing change?

[gemini-code-assist]

Summary of Changes

Hello @slin1237, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the project's multi-cloud capabilities by introducing comprehensive support for Oracle Cloud Infrastructure (OCI) authentication. It establishes a new, dedicated OCI authentication module, enabling the system to securely interact with OCI services using various authentication methods, including User Principal, Instance Principal, Resource Principal, and OKE Workload Identity.

Highlights

• New OCI Authentication Module: A dedicated pkg/auth/oci package has been introduced to encapsulate all Oracle Cloud Infrastructure (OCI) specific authentication logic, laying the groundwork for OCI integration.
• User Principal Configuration: The UserPrincipalConfig struct and associated methods (Validate, ApplyEnvironment) have been added to manage OCI API key-based authentication, supporting configuration file paths, profiles, and session tokens, with robust environment variable overrides.
• Generic OCI Credentials Implementation: The OCICredentials struct now implements the project's auth.Credentials interface, handling OCI's unique request signing mechanism (rather than traditional bearer tokens) and providing methods for region retrieval.
• OCI HTTP Client for Request Signing: An OCIHTTPClient has been provided to simplify making authenticated HTTP requests to OCI services by automatically signing outgoing requests using the configured OCI credentials.
• Flexible Authentication Factory: An OCI authentication Factory has been developed, capable of creating credentials for various OCI authentication types: User Principal, Instance Principal, Resource Principal, and OKE Workload Identity, centralizing the credential provisioning process.
• Comprehensive Unit Testing: Extensive unit tests have been included for all new OCI authentication components (config.go, credentials.go, factory.go), ensuring the reliability and correctness of the new authentication features.

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[gemini-code-assist]

Code Review

This pull request introduces an authentication module for Oracle Cloud Infrastructure (OCI), adding support for User Principal, Instance Principal, and Resource Principal authentication methods. The changes are well-structured. I recommend more robust parsing of environment variables, better error handling, and adjustments to HTTP client parameters.