fix(plugins): convert PluginOptionValues to Helm values

[IvoGoman]

Description

PluginOptionValues define the path for YAML fields. For nested fields the flattened paths, need to be unflattened.
e.g.

pluginOptionValues: 
  - name: disco.region
    value: qa-de-1

before would result in:

disco.region: "qa-de-1"

now it will be

disco:
  region: "qa-de-1"

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation Update
• 🎨 Style
• 🧑‍💻 Code Refactor
• 🔥 Performance Improvements
• ✅ Test
• 🤖 Build
• 🔁 CI
• 📦 Chore (Release)
• ⏩ Revert

Related Tickets & Documents

• Fixes 🐛 [BUG] - Flux HelmRelease does not support flat values #1314

Added tests?

• 👍 yes
• 🙅 no, because they aren't needed
• 🙋 no, because I need help
• Separate ticket for tests # (issue/pr)

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

Added to documentation?

• 📜 README.md
• 🤝 Documentation pages updated
• 🙅 no documentation needed
• (if applicable) generated OpenAPI docs for CRD changes

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes