feat(SCALE GUI): add gui options for volumeSnapshots (#14607)

**Description**
Adds SCALE GUI options for the soon-to-be-added volumeSnapshots

⚒️ Fixes #14605

**⚙️ Type of change**

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

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**✔️ 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

**➕ App addition**

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

- [ ] 🪞 I have opened a PR on
[truecharts/containers](https://github.com/truecharts/containers) adding
the container to TrueCharts mirror repo.
- [ ] 🖼️ I have added an icon in the Chart's root directory called
`icon.png`

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templates/questions/persistence/persistenceBasic.yaml

@@ -92,3 +92,30 @@
                   show_if: [["type", "=", "pvc"]]
                   type: string
                   default: 256Gi
+              - variable: volumeSnapshots
+                label: Volume Snapshots (Experimental)
+                description: Add an entry to the list to force creation of a volumeSnapshot of this PVC
+                schema:
+                  show_if: [["type", "=", "pvc"]]
+                  type: list
+                  default: []
+                  items:
+                    - variable: volumeSnapshotEntry
+                      label: Custom volumeSnapshot
+                      schema:
+                        additional_attrs: true
+                        type: dict
+                        attrs:
+                          - variable: name
+                            label: Name
+                            description: WARNING: renaming this, means deletion of the snapshot with the old name!
+                            schema:
+                              type: string
+                              default: "mysnapshot"
+                              required: true
+                          - variable: volumeSnapshotClassName
+                            label: volumeSnapshot Class Name (Advanced)
+                            description: For use with PVCs using a non-default storageClass
+                            schema:
+                              type: string
+                              default: ""

templates/questions/persistence/persistenceList.yaml

@@ -118,3 +118,30 @@
                   show_if: [["type", "=", "pvc"]]
                   type: string
                   default: 256Gi
+              - variable: volumeSnapshots
+                label: Volume Snapshots (Experimental)
+                description: Add an entry to the list to force creation of a volumeSnapshot of this PVC
+                schema:
+                  show_if: [["type", "=", "pvc"]]
+                  type: list
+                  default: []
+                  items:
+                    - variable: volumeSnapshotEntry
+                      label: Custom volumeSnapshot
+                      schema:
+                        additional_attrs: true
+                        type: dict
+                        attrs:
+                          - variable: name
+                            label: Name
+                            description: WARNING: renaming this, means deletion of the snapshot with the old name!
+                            schema:
+                              type: string
+                              default: "mysnapshot"
+                              required: true
+                          - variable: volumeSnapshotClassName
+                            label: volumeSnapshot Class Name (Advanced)
+                            description: For use with PVCs using a non-default storageClass
+                            schema:
+                              type: string
+                              default: ""