Add Filters to DO Images

[ccrvlh]

Adds a private and tag filter to DigitalOcean Images

Description

DigitalOcean accepts both tag_name and private parameters to filter images and Nodes. This PR adds these parameters using the ex_* convention. https://docs.digitalocean.com/reference/api/api-reference/#tag/Images Closes #1737

Status

• done, ready for review

Checklist (tick everything that applies)

• [x] Code linting (required, can be done after the PR checks)
• [ ] Documentation
• [x] Tests
• [ ] ICLA (required for bigger changes)

Others

First contribution, will keep it as a Draft for now.