chore(volsync): increase test coverage for specific usecases

[PrivatePuffin]

Description Primarily aims to expand coverage for stageclassname and volumesnapshotclassname

⚒️ Fixes #

⚙️ Type of change

• [ ] ⚙️ Feature/App addition
• [ ] 🪛 Bugfix
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] 🔃 Refactor of current code

🧪 How Has This Been Tested?

📃 Notes:

✔️ Checklist:

• [ ] ⚖️ My code follows the style guidelines of this project
• [ ] 👀 I have performed a self-review of my own code
• [ ] #️⃣ I have commented my code, particularly in hard-to-understand areas
• [ ] 📄 I have made corresponding changes to the documentation
• [ ] ⚠️ My changes generate no new warnings
• [ ] 🧪 I have added tests to this description that prove my fix is effective or that my feature works
• [ ] ⬆️ I increased versions for any altered app according to semantic versioning
• [ ] I made sure the title starts with feat(chart-name):, fix(chart-name): or chore(chart-name):

➕ App addition

If this PR is an app addition please make sure you have done the following.

• [ ] 🖼️ I have added an icon in the Chart's root directory called icon.png

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[PrivatePuffin]

I'm not 100% happy with this code/fix, but this should fix the issue of having to redundantly define storageClassName and fix the current rendering issues.

Which is kinda high prio, because it blocks using VolSync with a non-default storageClass atm