Update functions for plotting variants (4/P)

[AntoniaChroni]

Purpose/implementation Section

What scientific question is your analysis addressing?

To create functions to generate plots for variants: overall, per cancer group, and per kids_id.

What was your approach?

What GitHub issue does your pull request address?

This is related to the #41

Directions for reviewers. Tell potential reviewers what kind of feedback you are soliciting.

Which areas should receive a particularly close look?

Please review for code logic.

Is there anything that you want to discuss further?

Is the analysis in a mature enough form that the resulting figure(s) and/or table(s) are ready for review?

Results

What types of results are included (e.g., table, figure)?

What is your summary of the results?

Reproducibility Checklist

• The dependencies required to run the code in this pull request have been added to the project Dockerfile.

Documentation Checklist

• This analysis module has a README and it is up to date.
• This analysis is recorded in the table in analyses/README.md and the entry is up to date.
• The analytical code is documented and contains comments.

[naqvia]

lgtm!

[zzgeng]

Function works as intended. Look good to me! Approving