adding new ML modules for slips

[jsvobo]

Changes proposed

slips_files/

• Added new base class in common, that is a backend of ML modules
• changed zeek.py in slips_files/core to parse .labeled logs properly from the dataset repo
• updated config parser to read this new config
• in slips files/common, added a template for new ML modules

modules/

• added 2 new modules based on the class - ml_online_model and ml_linear_model
• added specific artifacts to LFS
• In the LFS, added online and linear model+pca+scaler

tests/

• added unit-tests for these three files

Others:

• updated config so we have new classes correctly configured from slips.yaml
• updated docs about training modules, models etc.

Steps you followed to test the changes purposed in this PR:

• Manually testing that no errors are raised by slips
• manually tested the new modules to make sure the resulting metrics are as expected

Check List (Check all the applicable boxes)

• My code follows the code style of this project.
• My change requires changes to the documentation.
• I have updated the documentation accordingly.
• All new and existing tests passed.
• This PR does not contain plagiarized content.
• The title of my pull request is a short description of the requested changes.
• My PR is based on develop branch. (mandatory)

[jsvobo]

Mashallah, the tests passed