feat: improve plugin config dependency

[junczhu]

Description

What this PR does / why we need it:

• Removed plugin config file loading when start server, in K8s mode, and only support CR loading (CLI mode still support config file loading)
• Added e2e tests and logs for new edge cases
• Further support multi-tenancy, which only support CR loading

Which issue(s) this PR fixes (optional, using fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when the PR gets merged):

Fixes #1104

• Remove config load for policy
• Remove config load for verifier
• Remove config load for store
• Add error log when doing verify in k8s and CR not found

Client:
K8s log:

Client:
K8s log:

Client:
K8s log:

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Helm Chart Change (any edit/addition/update that is necessary for changes merged to the main branch)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• Manual Test
• CI Test
• AKS Test: https://github.com/ZAFT-Armored-Keeper-of-Unity/ratify/actions/runs/7404003523/job/20144833117?pr=12

Checklist:

• Does the affected code have corresponding tests?
• Are the changes documented, not just with inline documentation, but also with conceptual documentation such as an overview of a new feature, or task-based documentation like a tutorial? Consider if this change should be announced on your project blog.
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have appropriate license header?

Post Merge Requirements

• MAINTAINERS: manually trigger the "Publish Package" workflow after merging any PR that indicates Helm Chart Change

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (b2bf323) 61.44% compared to head (36fb1c8) 61.69%.

Files	Patch %	Lines
httpserver/handlers.go	88.46%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1223      +/-   ##
==========================================
+ Coverage   61.44%   61.69%   +0.24%     
==========================================
  Files          97       97              
  Lines        6181     6192      +11     
==========================================
+ Hits         3798     3820      +22     
+ Misses       2051     2039      -12     
- Partials      332      333       +1     

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