Bump various Dockerfiles to v2 (with test stage)

[SarahNadeau]

This PR is to bump Dockerfiles to version 2 -- that means each Dockerfile has a test layer that runs a single bash script of tests. Each bash script does the following:

• verify the exact version of the tool
• wget a small dataset from https://github.com/nf-core/test-datasets
• run the tool on the test data using some common command configuration
• verify the checksum on an important output file.

---

• [x] Build your own docker image using a Dockerfile
  • [x] Includes the recommended LABELS
• [x] (Optional) Dockerfile is built with best practices and has been approved by a linter (such as https://hadolint.github.io/hadolint/)

I added TOOL_VER variables in Dockerfiles where the version was hardcoded throughout.

• [ ] Ensure tool is listed in Program_Licenses.md
• [x] Ensure a simple container-specific README.md exists in the same directory as the Dockerfile (i.e. spades/3.12.0/README.md)
• [ ] Update GitHub actions workflow if needed

I stopped adding workflows in anticipation of changing to a single test wf, single deploy wf that take the tool and version either from the directory structure or as manual inputs.

• [x] Any files required for building are located in the same directory as the Dockerfile (i.e. spades/3.12.0/my_spades_tests.sh)
• [ ] Have successfully run the workflow "Test image" in your forked repository

NA, see above. I've been checking the tests pass by building to the test stage on my laptop instead.