chore: Update ideascale/snapshot importer to use pydantic BaseModel a…

…s well as make it compatible with pydantic v2 | NPG-8105 (#554)

# Description

* Ideascale and snapshot importers now use pydantic's `BaseModel`
instead of `dataclasses.dataclass`
* Replaced `parse_obj_raw` for `model_validate` as it was removed in
pydantic v2

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?

I ran the importers manually.

## Checklist

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules