feat: support update ClamAV databases

[SteveLauC]

Standards checklist:

• The PR title is descriptive.
• I have read CONTRIBUTING.md
• The code compiles (cargo build)
• The code passes rustfmt (cargo fmt)
• The code passes clippy (cargo clippy)
• The code passes tests (cargo test)
• Optional: I have tested the code myself

For new steps

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• Optional: The --dry-run option works with this step

It should work

• Optional: The --yes option works with this step if it is supported by
  the underlying command

Does not seem to be supported

If you developed a feature or a bug fix for someone else and you do not have the
means to test it, please tag this person here.

Closes #743

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 5.36%. Comparing base (351922c) to head (eba10fe).

Files	Patch %	Lines
src/steps/generic.rs	0.00%	5 Missing ⚠️
src/main.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #747   +/-   ##
=====================================
  Coverage   5.35%   5.36%           
=====================================
  Files         37      37           
  Lines      12149   12145    -4     
=====================================
  Hits         651     651           
+ Misses     11498   11494    -4     

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